good evening guys am I Audible and visible to you all everyone am I Audible and visible hello hello hello good evening everyone ouch am I Audible and visible to you all okay hey okay okay okay okay okay is it Crystal Clear yes it is crystal clear so uh as you all know yesterday a small soft launch went on right uh about the neat 50 days challenge good evening everyone tal AR we forgot our entry hello SRI G from my side this this is your own physics educator indrajit Singh welcoming you all into the PW English Channel right yes I will teach you from scratch right lots of things are going to come in this today's session yeah it will be only English right yesterday you all know as you all know the small soft launch went on for the 50 days challenge right 50 days challenge for the upcoming neat examinations right 20 seconds refresh hello students am I Audible and visible to you all hello am I audible invisible sorry a small glitch went on okay is it now okay everyone those who are live okay so as you all know the small soft launch went on right in yesterday's session and we took a challenge 50 days need challenge so in this session lots of things are going to come I'm going to give you all the Mind BS on this session we're going to solve the sums we're going to understand the theories we are going to see the live simulations of it right it things goes awesome now when live simulations comes in front right things goes awesome when the Mind map comes in front things goes awesome when the questions are going to come in front yeah uh we will definitely discuss if any kind of the trick exist we are definitely uh in motion under Gravity lots of tricks are there in graph based question lots of tricks are there right yeah we will cover 1 D 2D both in 2D Riverman Rainman problem lots of tricks are there right okay harika says sir use China brush okay so sh we start everyone those who are live can have the answers into the can have the answers into the comment box right so the agenda of today's session is kinematics in the sense we are going to cover 1D and 2D both okay we are going to cover 1D and 2D both right are you all ready everyone those who are live can have the answers into the comment box please we will make physics see physics is not an a one minute process you can't understand physics into the one minute right so you have to wait till end this is what physics is all about you have to wait till end you need see we can't judge the picture by seeing first 10 minutes minutes you have to see the entire story likewise we can't judge the physics session right at the very moment in 1 second yeah this s is not good we can't do like that this s is not good he's having very long beard it's not like that you have to wait you have to stay till end you have to understand what actual content we are receiving and then judge right okay so as per neat syllabus the entire 50 days challenge will be divided into 20 units among them the first unit is kinetic kinematics 1D okay first we are going to see the Mind map of those chapters and then slowly slowly slowly slowly we are going to start the rest of the things okay so among the number of the students those who are watching those who think that this sir is this please bring that and this and this guys please it's your choice right okay we haven't kept gun on your head you're not on the pinpoint to watch this lecture right please okay so generally if I'm talking about 1D 1D motion starts with the basic terminologies the basic terminologies means what we are going to discuss about distance we are going to discuss about displacement we are going to discuss about velocity we are going to discuss about average velocity we are going to discuss about speed right we are going to discuss about average speed right acceleration average acceleration right this all are the basic terminologies that are used into the 1D okay understood everyone those alive okay so this are the very basic terminologies as we are dealing with Motion in one dimension as we are dealing with Motion in one dimension right so I have included this much terminologies apart from this we will be having the force right lots of things are there but later they will be we discussed later on okay as the cabus continues the rest of the physical quantities will be introduced now the second thing jumps on to motion right okay you can also say that second thing jumps on to the motion now how we are having further bifurcation of the motion first the type of the motion that we are going to discuss will be uniform motion what is the meaning of uniform motion I think now I'm perfectly Audible and visible right okay now I'm perfectly Audible and visible right we are living into the technical worlds and we are having some glitches right okay so the first part that's a uniform motion uniform motion it means simply speed is constant right uniform motion nothing it tells nothing about distance it tells nothing about displacement it tells nothing about average velocity average speed and everything right it only states that uniform motion the speed is constant the second type of the motion that is known as uniformally accelerated Motion in this uniformly accelerated motion we are having the simple explanation as acceleration of the system is constant and when acceleration of the system is constant we are having the two equation three equations right so these are the three equations in which the acceleration of the system is kept constant right now on another side it comes motion under Gravity where acceleration is constant but it is negative G so this three equations can be written as v isal u minus GT s = to U -/ GT s v² - u² = 2 GS so this is what the classification of the uniformly accelerated motion goes on basically in this chapter you're going to deal with three types of the motion first is uniform uniformly accelerated third is non-uniform motion right so here third type of the motion comes upon as nonuniform motion right non uniform motion understood everyone those who are live can have the answers into the comment box please now third bifurcation of this mind map goes on to the most important method that is applicable to all kind of the motion that is calculus method that is what calculus method right that is what calculus method understood everyone those who are live that is what calculus method after calculus method after like basically there are three formulas included into the calculus method a is equal to DV by DX V is equal to DX by DT right and acceleration is equal to DV by DT whether it is a uniform motion non-uniform motion uniformly accelerated motion whatsoever it should be or whatsoever it may be right the entire calculus method relies on these three formulas okay and the final last and the final bifurcation okay that went on graph and graphs conversion entire motion into 1 d right entire motion into 1 day is covered in this mind map okay see we are into the last 50 days challenge if you are expecting that into the two or 3 hours of the lecture we will do differentiation also right the polishing of the neat content is going on right guys polishing of the neat content is going on so please understand the sensitivity of this lecture are you all okay with this everyone those who are live can I have the answers into the comment box everyone first and now what we are going to do we are going to see lot lots of numericals of the 1 day and through each and every numerical see if I'm going to tell you all the theories and then we will do the numericals at the last moment then it would be the very lengthy process but what once we are going to see the numerical and through that we are going to revise the theory it means that in each and every numerical we are revising the whole chapter so that's called an reverse engineering and we are going to follow that each and every sum will come in each and every sum I will explain you the whole whole Theory so through this we will be having the two benefits the entire theoretical part will also be covered with the revision in this session only and lots of numericals we are going to solve see directly one question will only come from this chapter but indirectly this kinematics is useful in all in entire cabus okay shall we start everyone in the diagram shown a particle moving from a point A to point B length of each arrow is 1 M and the particle is moving with a constant speed what is the displacement displacement okay so before solving this numerical let's move on to the distance displace okay now we are going to see the terminologies that are associated with the uniform motion okay terminologies that are associated with the uniform motion first distance second displacement speed velocity average speed average velocity student always used to get confused in between this terminologies and we are going to clear all of those terminologies in one shot and we need to that we will Define a uniform motion done distance total length of Journey which is sometimes it is also known as path length distan is always positive it can't be negative what is displacement shortest distance between two point it can be positive it can be negative it can be zero sweet sober direct explanation what is speed speed is the factor that is associated with the distance traveled by time is speed always positive velocity displacement by time as displacement can be positive negative 0 the velocity can be positive negative and zero average speed is total path length by total time generally average speed is taken into the calculation in those cases where entire journey is broken in multiple Parts you might have heard about this question particle starts for 2 second with this velocity and then moves for 3 second then this velocity and then moves for 4 second with this velocity for this kind of the questions right the entire journey is broken okay into the multiple Parts in that case average speed is calculated and what you want to tell about the average velocity is displacement by time right understood everyone so this is what the very basic explanation of the distance displacement average speed average velocity right and distance is all about okay now if I'm going to tell you all about the uniform motion then we are having the very simplest explanation of the uniform motion the speed of the particle is constant it means the ratio of Distance by time traveled is constant this is only the simplest explanation of the uniform motion right this is only the simplest explanation after the uniform motion now what does the question demands when particle moves from A to B what is the shortest distance each length is 1 m 1 m 1 m 1 M they are saying what is displacement displacement see this is an initial point and this is the final Point as we discussed displacement is the displacement is the shortest path between the initial and final position this is what we have discussed now shortest you can case shortest distance you can say shortest path right you can say shortest path between the two points okay so what is the shortest path 1 m + 1 M your answer is 2 m okay the question was quite easy but it was kept at the beginning of the session to make you all aware about the process that we are going to follow for the entire session right okay so this is the question and this is the theory revised let's move on to the next question again see from the same then numerical ratio of distance or displacement to distance covered is always can you have the answers into the comment box see we have to find the numerical ratio of displacement to distance right displacement is the vector quantity as we are dealing with the 1D motion so as of that reason we aren't introducing the vectors but displacement is actually the vector quantity and here the new aspect of the theory is coming can have the answers please into the comment box for this can anyone try the new aspect of the theory is Right distance is always magnitude of displacement distance is always the magnitude of the displacement suppose let us take an example if I'm saying r isal x of I + y of J plus Z of K the 3D Vector is given suppose they are saying this is the placement Vector right then magnitude of this will be the distance so what is a magnitude under root of x² + y s + z s so here the possibility arise that if it is displacement or distance ratio the maximum value of the displacement can be distance you can also say that maximum value of the displacement is distance so as of this reason this ratio is going to be less than equivalent to one understood everyone those who are live can have the answers into the comment box please please yes or no is it cool right this was a theory this was a uniform motion that we understood from the first sum this is the new aspect see whatever the new things that are coming up in front you can just write down at the bottom like that way right okay let's move on to the next question see the car travels a distance day on the straight road in 2 hours and then return to the starting point in next 3 hours entire journey is broken right or entire journey is divided into multiple parts right this is what I said now here the concept of average speed comes when entire journey is broken like it is divided into multiple Parts see same theory for the third question so with each question we are revising the same Theory thce and we are solving the numericals also so this is the power of the reverse engineering and this is what we are going to do into the need 50-day challenge a car travels the distance D first time interval in 2 hours then returns to the starting point it starts from A to B and then returns to the starting point it means it travels the same distance in 3 hours see the entire journey is divided into two parts so as of that reason they are asking you to calculate the average speed okay so what is the formula of the average speed here the formula of the average speed that is is equal to total distance right by total time so total distance is D + D total time is 3 + 2 okay your answer is 2D by 5 m/s understood everyone those who are live was it easy or not can I the answers into the comment box from the number of the students those who are watching this session live right guys see the same Theory average speed total path by total time okay let's move on to the next question now particle starts its motion from rest under the action of constant force here comes the new thing here comes new thing how it is so possible you can introduce the force in 1D kinematics is that branch of the motion in which study is done without cause study is done without cause without understanding the cause of the motion right we are see you are an being a student you are an observer I am an observer let us take an example from the very day-to-day life right ideally you are sitting as usual I used to take the same example in my uh app batches ideally you are sitting scrolling up the Instagram so your motion before 50 days of need might be like someone might be analyzing this motion now who's the one Mama all the time and you all are like right so who's a frame of reference frame of reference The Observer is a frame of reference who mom in this case is a Fame of frame of reference right who is the subject I am a subject what I'm doing performing motion like that so in this case whenever the frame of reference observes the motion to the subject he never thinks about the Cause right instead of mother if the Observer might be your brother or something now who is going to tell him again and again he's not going to be serious but instead of your brother or someone else it's your mother if it would be your brother he would be your brother he will think without cause if it would be your mother she would be your mother she will think with cause so many students might be thinking as we are dealing with the kinematics Motion in one day how cause will come constant force it means we can say it there as F isal to ma a force if force is constant acceleration is constant so indirectly they are telling us about that acceleration is constant if acceleration is constant then what kind of the force is going to come within if acceleration is constant then this is purely the case of uniformly accelerated motion what is uniformly accelerated motion a very simple very awesome example I'm going to give you all in front one example entire topic will be into fitted into your head acceleration of the particle is constant velocity increases or decreases at uniform rate what is the meaning of the velocity increases or decreases in the uniform rate what is the meaning of this uniform rate uniform rate it means what suppose particle starts from rest if in first 5 Seconds velocity is increasing by 5 m/s then in next 5 Second also it will be increasing by five in third fifth second it will be increasing by five in fourth 5ifth second it will be increasing by five okay suppose particle starts from rest t is equal to 0 U is equal to 0 in first 5 Second it increases by five then in next 5 Second also it will be increas increasing by five in third 5c also it will be increasing by five in fourth 5 Second also it will be increasing by five so this is a uniform rate of increasing into the velocity similarly uniform rate of decrease in velocity will come so whenever we are having this kind of the motion we have must say it is in a uniform accelerated motion and three equations are associated s equal to UT +/ a s v equal to U + a okay this equation you have to apply when you have to find velocity at any time this equation you can apply when you want displacement at any time and this equation is a applied when you want to find anything between two time intervals should I give you the best example have you heard about the music Sorry being into the pure English class right I can't sing uh that western music so I'm just giving you the example of the uniform accelerated motion the velocity is increasing at the uniform rate velocity is constant velocity is constant uniform velocity is increasing with respect to [Music] time velocity is decreasing with this is the best example of the uniformly accelerated and uniformly decelerated motion see velocity is increasing it is starting from rest it is increasing [Applause] to right we are first priyaa we are first seeing the concepts only and then we are solving the sums right so this is the case of the uniformly accelerated motion did you all understood the concept can we move on to the sum you just have to think about the acceleration is constant where wherever the acceleration is constant you can apply these three equations if acceleration is constant velocity might be increasing or decreasing at the uniform rate you can apply this equation acceleration constant you can apply this equation acceleration constant you can apply this equation or you can [Music] remember now they are saying see if the distance covered in first 10 second is S1 and covered in first 20 second is S2 simply here time distance time distance we have to use second equation right so S1 is zero as it starts from rest first 10 seconds so S1 that will be a by2 into 100 that is 508 can I consider this is equation number one the distance for the first 20 second is S2 right so 20 is equal to 0 + half a 20 whole s S2 so S2 is equal to ax2 into 400 so S2 is equal to 200 a can I consider this as equation number two they are telling us to find the relation between S1 and S2 so can you all tell me the perfect answer S1 by S2 that is is equal to 1x 4 S2 is = 4 S1 understood bet everyone those who are like can have the answers into the comment box so from this question right we understood right from the previous two to three questions we understood the concept of the uniform motion now from this right we understood the concept of the uniformly accelerated motion right see everything is having the preparation scenario if you are joining the batch from the beginning and preparing for two years see first of all I'm going to clear out that thought it is not possible to teach the 2-year entire 2-year content in 3 hours if you are thinking that entire two year content should be taught in this that is not so possible right and whatever the thing that we are doing here it is best understood with everyone those who are like okay let's move on to the next question see speed of the two identical cars are U and foru at a specific instant see this is a specific instant car a a car B speed of the car a is U speed of the car B is 4 U it means initial speeds are given right initial speed it means at T is equal to Z T is equal to 0 means the point where Observer starts observing its motion right okay Observer starts observing its motion musan nazia then why you write score 700 plus you can you can whatever the content we are discussing it is capable enough to polish your knowledge right no one is blamed here and no one is misleaded here right you can right beta but if you are expecting only from one session I will score 700 then your own psychology is wrong right the ratio of the respective distances when two cars are stopped see here they are talking about the concept of stopping distance right here they are telling us now what is an actual meaning of the stopping distance stopping distance means quite simple right stopping distance it means see practically speaking when acceleration is in direction of velocity it increases the speed of the particle and when acceleration is in opposite direction of the Velocity it decreases the speed when acceleration and velocity both are into the same direction it will increasing the speed and when acceleration and velocity both are into the opposite direction it will decrease the speed understood so here stopping distance comes when particle starts moving with the initial velocity acceleration retards it is into the opposite direction and velocity decreases at uniform rate velocity decreases at uniform rate and after some amount of the time it stops so here if we am using the third equation of motion right final velocity becomes zero this is the formula of stopping distance stopping distance is nothing else but the accelerated motion only stopping distance is just one of the application of the accelerated motion only right stopping distance is just one of the explanation of the accelerator motion only here in this case the difference is acceleration is only negative in uniformly accelerated motion acceleration and velocity are into the same direction it increases the velocity to and when acceleration is opposite direction to the velocity it is a retardation deceleration both are the same words so this is the concept of the stopping distance and now we are going to use this into the formula see from this formula can we say the stopping distance is directly proportional to U sare so can we say S1 by S2 that is is equal to U1 Square by U2 squ U and 4 U so S1 by S2 that is equal to 1 is 16 answer is quite easy Once you are able to understand the concept the things are quite easy done everyone those who are live can have the answers into the comment box is it done can we move forward to the next question guys you all are enjoying now you all are enjoying the explanation and the way of teaching now average velocity of the car between two c is 20 if it moves with 50 for half of the total time okay now here in this question we are going to introduce the new thing right see in case of uniform motion two special cases are there in case of uniform motion you all know what uniform motion is uniform motion is speed of the particle is constant now we are not talking about the uniformly accelerated motion still many students are thinking sir why you jump down from uniform to uniformly accelerated now again you're going back to uniform same happens in need right same happens in need if you are expecting the first question of the need is going to definitely come from units and measurement wrong second question will be definitely from 1D wrong third question would be definitely from 2D nlm right if they're going to follow the sequence wrong anything may come upon any time if you are having an habit to deal with things like this then and then you will feel comfortable into the neat examination see in neat examination what happens one side your two years of the preparation and another side 3 years of exam sometime exam pressure is at so pick that the two years of the preparation is at full stake comparing to the 3 hours of the examination and this happens only into the case right okay this happens only into the case when you all are not perfectly aware about an exam environment so why here things are going on randomly because we if particle start from a ands then B entire journey is divided into two equal distance intervals this is the case of two equal distance intervals this distance interval V1 this with V2 then average speed it is given as 2 V1 V2 whole divided V1 + vs2 this is special case number one now we are moving forward to the spatial case number two instead of two distance equal distance intervals Right Here Comes equal time intervals so in this case average speed or velocity it is given as V1 + vs2 ided 2 so whenever the two equal distance intervals are given into the question you can use this direct formula when the equal time intervals are given you can use this direct formula right so here in this question they have mentioned h half of the total time see kindly focus on the journey the entire journey is divided in two parts the entire journey is divided into two equal time intervals for first half time intervals this is a velocity so it means directly we are going to use the formula average velocity or speed that is V1 + V2 divided by 2 the total journey is 200 is 50 + V2 ided by 2 so what will be the V2 350 m/s right so the diagram appears like for first time interval for second time interval right this is with 50 right and this is with 350 understood everyone those who are live great understood guys are you all live you all are breathing all are breathing now yes or no guys you want this Peg no it's not a peg right it's just a water you can just see and it's just a water okay so this is the theory the special cases of of the uniform motion right can we move forward a car starts from rest and accelerates uniformly see accelerates uniformly it means it is the case of uniformly accelerated motion among this three equations we are going to get the answers it starts from rest reaches to 180 in 10 seconds then distance covered by will be what particle starts from zero reaches to 180 km per hour in 10 seconds I think he is traveling Bugatti he traveling through Bugatti and Bugatti what Aston Martin right in 10 seconds it's goes from 0 to 180 [Applause] and 0 to 180 0 to 180 would be like 0 to 180 0 to 20 would be like 0 to 50 would be like 0 to 100 would be like to and 0 to be like to initial velocity is zero final velocity is 180 km/ hour right so if I'm converting 180 kilm into 5 by8 18 so your velocity will come upon in 50 m/ second so initial velocity is zero final velocity is Right 50 time see they have said that it is a case of uniformly accelerated motion but acceleration value is not defined if you are unable to define the acceleration value how will calculate the distance so first step is from the given data find the value of acceleration right final velocity is 50 0 acceleration into 10 the particle is getting accelerated by 5 m/s Square oh we got our acceleration it is constant now what we need to calculate distance covered by the car in time interval distance covered by the car in time interval what distance we can use this equation U is zero in 10 seconds this is our answer understood everyone those who are live right is it easy or not uhuh is it easy or not again car starts from rest rest u0o accelerates uniformly it is a case of uniformly accelerated motion why we converted you can keep in kilometer per hour see time was in seconds right generally we are solving maximum numericals into MKS system time was in seconds suppose if you're not converting the velocity from kilometer per hour into meter per second right then converting time from second to hours will be the time consuming process right you can understand again see 144 kilomet in 20 second the distance covered in 20 second is the same procedure we need to follow can we do that everyone those who are live H if you want to convert kilometer per hour to meter per second you have to multiply by 5 by8 or if I'm going to give you all the shortcut on every 36 kilom per hour you will be having 10 m per second 72 km/ hour 20 m/ second right in between 32 36 to 72 you will be having 5 m per sec or 15 m/ second on multiples of 36 36 10 10 m/ second 72 20 m per second 144 40 m per second so this is a shortcut trick that will save your time into an examination can we do this sum by ourself everyone those who are live can I have the answers into the comment box please we can do it by ourselves yes or no everyone those who are live right which of the the following relation representing displacement particle with a constant acceleration aha calculus method the previous previous question I gave you all in homework because it was the same procedure that we followed into the right see the same procedure that we followed here the procedure that we followed in this question the same we are going to follow in this so I've G given you all in homework now we are going to see the different aspect of the uniform uniform L accelerated motion that is a calculus method boom entire calculus method depends on three important formulas and a trick entire calculus method depends on three most important formulas in the trick the first most important formula is a equal to V DV by DX the second most important formula is V is equal to DX by DT among this three formula only the entire calculus thing is defined among this three formula only the entire calculus thing is defined and with this one trick if you are following top to bottom if you are going from displacement to velocity velocity to acceleration you have to do differentiation if you are following bottom to top approach you have to use integration so this is a trick and this is the formula one side we are be we will be having a trick on another side formula understood everyone those who are live okay differentiation of displacement always gives velocity differentiation of the Velocity with respect to time always gives acceleration integration of acceleration with time always gives velocity it gives change in velocity right and integration of velocity with respect to time it always gives the displacement understood everyone those who are alive right so let's see what they are saying into the question okay see from this calculus method only you can Define the uniform motion The uniformly Accelerated motion non-uniform motion all all kind of the motion into the 1D can be defined by this calculus method whether it is uniform uniformly accelerated and all right let this entire 50 days challenge should complete and then see revolution in yourself uh this is what I said into the beginning of the session now please don't judge into the first 15 minutes 20 see one hour of the class had been 1 hour is crossed time flies right you all are enjoying now everyone those who are live see we need to check it out in which equation acceleration is constant C suppose if I'm taking equation number three x is = 90 Square by 8 differentiating this equation with respect to time it is is equal to 18 T right and acceleration will be 18 m/s squar in the third each and each and every equation of the displacement is given right each and every equation of the displacement is given each and every equation each and every option you have to differentiate it twice to reach up to the equation of the acceleration because see here displacement is given and we have to reach up to the acceleration displacement is given then we have to reach up to the acceleration so what we have to do we have to follow the top to bottom approach displacement velocity velocity time are acceleration so you have to differentiate twice this equation twice this this and this right each and every option you have to analyze with whatever the data that is given into the question so from this third is only the thing right in which we are going to have after differentiating it twice we will be having the constant value of the acceleration so third is a perfect answer for this specific question understood everyone those who are live see if a train traveling at this speed is brought to be rest in distance of 200 what is a retardation can we use direct formula of stopping distance yes or no in this question can we use the direct formula of stopping distance yes or no in this question everyone those who are live everyone if a train is traveling at the 72 km/ hour and it is brought to be at rest in 200 M then its retardation should be what directly can we use the formula now s equal to u² by 2 a retardation is equal to u s by 2 s what is U 72 kilm it means it is 20 m/s 20 into 20 all divided by 2 into 200 retardation is 1 m/s square stopping distance train stops in 200 M it means stopping distance is given right understood everyone those who are live see X denotes displacement acceleration is what which approach we need to follow in calculus top to bottom or bottom to top displacement is given we need to find the acceleration what approach we need to follow top to bottom bottom to top can you all ask answer into the comment box please can you all answer into the comment box x isal a COS of t differentiating with respect to time we will get velocity differentiation of cos is minus s right again differentiation of velocity with respect to time we will get acceleration is negative of a COS of T this was a very simple question based on write the calculus method very simple question based on the calculus method understood everyone those who are live yes or no the displacement of the particle is given by this two equation acceleration of the particle is what again displacement is given we have to find the acceleration you only tell me top to bottom bottom to top now you are capable enough displacement is differentiating with with respect to time 40 + 2 differentiating with respect to time ADV question the J Advanced students are not going to come in this sessions right because this is a neat based thing is going on again position of the particle varies with respect to time acceleration at the time T of the particle will be equal to zero they are asking at what time acceleration is going to be zero displacement is given X is equal to a t² minus BT Cub they are asking at what time acceleration will be zero top to bottom bottom to top we have to reach to the acceleration from displacement so we need to follow top to bottom approach right okay so velocity will be what velocity is 2 a t - 3 BT s acceleration will be 2 a - 6 BT we need to make it as zero so 2 a - 6 BT is equal to 0 right so 2 2 a is equal to 6 BT so the time at with the acceleration would be zero 2 3 are a by 3B this is the perfect answer for this specific question understood everyone those who are live see again displacement now they are asking what will be the acceler what will be the velocity when acceleration is zero can we do this by ourself yes or no everyone those who are live can we do it by ourself yes or no everyone top to bottom approach find out the equation of acceleration in that find out the time replace the time into the equation of the Velocity to get the final answer that's it now we are coming up to the case of the mo motion under Gravity motion under Gravity shall we start the most important lots of Tricks into the motion and the gravity are going to come please give okay unique first of all the stone thrown upwards with you from the top to B reaches the ground height of the tower is what motion and gravity motion under Gravity lots of tricks are going to come okay the motion under Gravity is simply as like particle is thrown with some Vel City it goes up follows the same trajectory and comes down do you want the live simulation of it everyone do you want the live simulation of this H guys do you want the live simulation of motion under Gravity see particle is thrown with the initial velocity into the upward direction see okay I'm decreasing the velocity so that you are all are able to understand see are you all able to analyze are you all able to analyze yes or no everyone those who are live object is thrown from the bottommost surface the object is thrown with some velocity it follows the straight line trajectory and retracing right it comes back retracing the same tra okay same simulation we are going to see for the projectile motion okay same simulation we can see for the horizontal projectile motion obl projectile motion horizontal projectile motion motion under Gravity are you all able to understand being an observer you are the Observer being an observer whenever you are trying to analyze this right whenever you are trying to analyze this and writing down into the paper it is equivalent to studying physics in this world there are no free lunches in life right but this always gives the feel of physics right this always gives feel of physics right now see what happens to the case of the motion under Gravity see motion under Gravity what happens in this case see there is a ground particle is thrown upward with the initial it reaches to the max height and retracing its path it hits the same point right it is given some velocity it goes into the upward Direction reaches the maximum height it retraces its path and hit back the same point right with the same magnitude of the Velocity but the direction is revers so here as Galileo said that this kind of the motion always comes under the constant acceleration that's why we can say it as this motion is motion under Gravity motion under Gravity motion under gravitational force there is a force there is an acceleration from the center of the earth that tries to pulls every object there is an acceleration that try to pulls every object towards the center of the earth as of this reason it is known as the the motion under Gravity understood everyone okay so as acceleration is negative okay but it is constant so we can apply the we we can use this three equations okay now what are the tricks into the case of the motion under Gravity see whatever the things goes up same comes down if the object is thrown with 10 it will hit back with 10 if the object is thrown with 20 it will hit back 20 when the object is thrown with 30 it will hit back with 30 when the object is thrown with 40 it will hit back to 40 and there is a trick if it is thrown with 10 it will reach Max height in 1 second if it is thrown with 20 it will reach the max height in 2 seconds if it is thrown with 30 it will reach Max height in 3 seconds 10 1 second if it is thrown with 20 2 seconds if it is thrown with 30 3 seconds this is a trick and at Max height the final velocity is always zero understood everyone those who are live right now this question states that this question is bit different it states that a stone is see there is one Tower of height Edge a stone is thrown upward with the velocity U it travels to the max height and hit backs the ground with The Velo CT 3u and we need to calculate the top of the tower huh if the velocity is given with which the particle is thrown in upward Direction then it is quite easy to calculate the time of flight and time to reach the max height right understood okay understood guys so here what we are going to do this is the initial point in between initial and final point we are going to apply the third equation of motion final velocity is 3 u s 9 U sare initial velocity is u s netive of 2 g h is the height of tower 8 u² is equal 2 g h so H isal 4 u² by G so this is the value of the height of the Tower understood everyone those who are live right 8 u s by G okay is the height of the Tower understood it is array sorry sorry sorry sorry sorry 4 U S by G my mistake 4 U S by G okay understood everyone Yeah by my mistake so through this question we have revised the concept of the motion under Gravity now through this question we are going to revise the all the concept of graph a body is projected vertically upward from the surface of the Earth it velocity versus time graph would be what see graphs of uniform motion what is the meaning of uniform motion speed is constant right so it means what the X versus T graph would be like this way right V versus T graph would be like this way and acceleration would be time would be be zero these all are the graphs of the uniform motion king of physics oh right the next Comes The uniformly Accelerated motion right XT graph is like this way velocity versus time graph is like this way acceleration versus time graph is like this way acceleration is constant in uniform motion speed is constant in uniformly accelerated motion acceleration is constant right okay in non-uniform motion nothing is fixed see this are the standard graph if something different comes right from the standard procedure you all might be thinking now the question what they are asking is not a part of the standard procedure right then what you are going to do there might be some way so in this case what you have to do if any graphs comes on extraordinary different from the standard graphs that are given into the ncrt what you have to do you have to trace the value at each and every Point Trace trace the value at each and every point you will get your answer you will definitely reach up to your answers see this is a ground from ground the particle is thrown up Wards here the velocity is maximum means it starts from here the graph starts from this position slowly slowly slowly slowly slowly slowly when particle reaches the max height velocity is zero it means from ground to Max height from ground when it starts and reaches to the max height velocity becomes Zero from ground it starts when reaches to the max height the velocity becomes zero it means here velocity is decreasing to zero now when it come backs see velocity is the vector quantity when it was moving up the velocity Vector was in upward Direction so we took it as positive now when it is retracing its path the direction of the Velocity is downward so we will take it as negative right so when it retrace its path velocity is increasing but it is increasing into the negative direction right so like this way point to point you have to trade trace the value of the physical quantity and plot the graph now still many students are thinking sir why the graph is a straight line why it is not a curve or something because velocity always follows this equation right so as of this reason the second is the perfect answer for this specific question second is the perfect answer for the specific question understood everyone everyone those who are live can you have the answers into the comment box please are Y how it is going to start from zero suppose the velocity no velocity is given to the particle then how it is going to reach Max height if some velocity is there at the bottom then and then it is going to travel some distance and reach to the max height particle starts from rest and moves with the constant acceleration it velocity displacement see standard graph V ² - u ² = 2 a s parabolic graph this is the equation of Parabola y² is directly proportional to X equation of parabola equation of Parabola for this v² is directly proportional to s for this V is directly proportional to x square according to the standard equations of the parabola are this is a velocity versus displacement for the constant as acceleration is constant it means we have to use the third equation of acceleration or third equation of the uniformly accelerated motion the third equation of uniformly accelerated motion only defines the relation between velocity and displacement understood everyone those who are live which of the following velocity time graph shows the realistic situation which is the realistic situation you only tell me analyze the graph and tell me the realistic situation into the comment box please everyone those who are live please and please do share this session maximum in your groups with your friends and all see time always moves in forward Direction how it is so possible time moves back time always moves in forward Direction ction how it is so possible time moves back in this three graph time moves back this is only the graph in which time is moving in forward Direction sometimes you have to think logically and get the answers right sometime you have to think logically and get the answers from the following time versus displacement find the velocity oh very simple slope of displacement versus time graph is velocity yes or no slope of displacement versus time graph is velocity but here time versus displacement is given so slope is equal to 10 Theta that is is equal to Velocity but here as it is time versus displacement so here 1 by slope will be equivalent to Velocity reverse graph is given if it would be displacement versus time then slope will be velocity then it will be 10 Theta as reverse graph is given 1 by slope 1 by 10 Theta is velocity so velocity is equal to 1 by 1030 understood should everyone those who are like so this kind of the tricky I must not say tricky catchy right equ questions are also coming up into an examination calculus method find the nature of the acceleration X is equal to bottom to top AR top to bottom velocity is 2T + 4 acceleration is 2 m/s squar 10 seconds right question is solved distance clear displacement clear velocity acceleration average acceleration uniform motion clear the three equations are clear right uniformly accelerated motion non for motion it's okay calculus method is clear we have seen some graph based question see practically you all also all are mature right that there is a difference in the 3 hours of the or two and a half hours of the lecture and the huge preparation so here this lecture has been kept to you all to polish to score 650 or 700 marks is not a one-time process it is an entire Journey slowly slowly slowly slowly slowly slowly slowly slowly slowly right you are raising yourself right okay now one says you sorry sir but you are little you are really an in immediated you are judging in one minute okay now I'm going to give you all the Mind map of motion in 2D now T is having vectors see speed is more than fine it you can say it is an appropriate you also know see if I'm talking about our regular classes if I'm talking about our sessions even if I'm talking about our dropper session okay we took one lecture to explain the entire concept you can't eat Chapan B in one second now you can't eat chap B even in an hour because your stomach is not having that much volume to eat to acquire the Chapan B you will spit out right so this all sessions are kept for you all to polish your knowledge see I'm not in culprit if I'm saying truth I don't want to make you all right uh into the false hopes right 700 720 is a journey that starts from suddenly 50 days before the need the student who has already crossed the two years and reach here and now you anyone wants to jump even in this case luck is not going to support right beta so this kind of the sessions right I just help you all for in right polishing your knowledge at least you know something before and after this lecture everyone yes or no those who are like the first part of 2D goes to the projectile motion basically three types of projectile motions are there right basically write three kind of the projectile motions are there the first one which is known as obl projectile motion the second one it is known as horizontal projectile motion and the third one it is known as inclined plane projectile obl projectile it means what projectile is thrown at some angle horizontal projectile it means projectile is thrown from some height inclined plane projectile it means that projectile is thrown from some inclined plane this are the examples of the projectile motion understood the second part relative motion first case of relative motion Rainman problem we will discuss the shortcut there is a shortcut for Rainman problem Riverman problem there are two cases into the Riverman problem and we are having the shortcut and the last case goes to circular motion among them uniform circular motion UCM non-uniform circular motion n UCM so this is the chart of 2D the circular motion uniform circular motion non-uniform circular motion can be taught separately into the work energy and power chapter don't get worried in today's session we are going to review projectile motion and types of projectile motion relative motion and I'm going to give you all the shortcuts for Riverman and the rainmen problem see projectile motion is all about direct formula you have to understand the concept once apply formula get the answer understand the concept once apply the formula get the answer understand the concept once apply formula and get the answer Riverman and rainment problems are like that only understand the sum identify the case apply the formula and get the answer identify the sum understand the case apply the formula and get the answer everything is systematic yeah and this is just an students always need in a last minute things they are always having a thought they are always having a thought right immediately everything should scroll into my mind and through mind maps each and every topic is going fast and you are able to you are capable to remember you are capable to scroll each and everything and memorize it so for them mindmap is the best technique right right yeah important thing with the preparation see whenever you are appearing into the neat examination the important thing into the presentation the preparation is in the exam is it is important to remember everything s time P say cheese right time right moment right things should come up into your mind and it always this always happens with right whenever you do the more amount of the revision yes the right moment if you are able to recall things understood everyone okay so now can we move for forward to the concept of obl projectile motion right uh I want to ask you all one thing you all are really enjoying this session now at least your knowledge is getting enhanced at least your knowledge is getting polished before and after this lecture you all are feeling good now because see this is what we are doing in English suppose just imagine if this thing goes in Hindi right so you can imagine the level of this session right I can understand very less students are there but it's okay right we are good in what ever the students those who are present into this class because see 2 hours of the class see how time flies only 5 to 7 minutes are remaining in 2 hours of the class right obl projectile motion see this is very simple obl projectile is quite simple classroom teacher who's doing mcha Focus write down who is there this happens with everybody yes or uh we are having Yen English batch pure English right that will come and rest of the details okay new batches are coming this year but let's see okay now we are coming back to the same example you [Music] this what happens into the school life and we are also damn right we all we are we are also like like we are even a stubborn peop that we never used to stop harassing our school teachers and now again teacher is like projectile he throws a chalk to a student teacher should be like into the classroom generally it happens whenever she or he used to write it into the right board okay this is the moment for the students an opportunity right it is an opportunity for the students to do an right Mischief so whenever teacher used to write and teacher behaves like and throws chalk chalk is thrown at some angle with respect to ground it travels the traj eory this kind of the motion is projectile understood everyone this kind of the motion it is what projectile okay I must say it is a now see as you all know this is a motion in 2D as you all know this is motion in 2D right Motion in 2D so here when you are resolving the components of U this will be U sin Theta two types of motions are involved one into the horizontally X Direction two types of motions are involved the resultant of horizontal and vertical is projectile see it is a 2d motion once you are able to understand the concept now you will understand everything are we having any kind of the acceleration to increase or decrease the U cos Theta are we having any kind of the acceleration into the horizontal direction right are we having are we having any kind of the acceleration in the direction of U cos Theta or in the opposite direction of the U cos Theta no it means acceleration along the X direction is zero the nature of the horizontal motion is uniform the nature of the horizontal motion is what uniform the example that I gave is not to disrespect teachers it was just an comic moment to to explain the example into the most convenient way because this is a physics right so being a teacher I can't hurt the sentiments right so it was just an disclaimer just for an understanding purpose right so horizontal motion is uniform now see there is a gravity gravity is there to decrease the U sin Theta and again increase it so if I'm talking about the nature of the vertical motion acceleration is there so vertical motion is uniformly accelerated motion understood so what is the nature of the horizontal motion uniform what is the nature of the vertical motion uniformly accelerated resultant of this two is obl projectile this is the actual concept this is an actual logic behind it now suppose now generally whenever the obl projectile is taught okay they used to teach about the direct formulas and they said formula based questions are I am following a different approach if the projectile is a resultant of horizontal and vertical it means the displacement is also the resultant of horizontal and vertical horizontal is uniform all the formulas of the uniform motion I can apply in horizontal nature of the vertical motion is uniformly accelerated all the formulas of the uniformly accelerated motion I again apply here see this is the displacement Vector velocity into time is distance for vertical U sin Theta - half GT s j it became easy or not everyone those who a l resultant of this two is projectile velocity velocity into the horizontal Direction plus velocity into the vertical velocity into the horizontal is constant velocity into the vertical G is decreasing U sin Theta minus GT these are the two equations right from which trajectory range Max height all the spatial cases of the obl projectile motion are defined from this two cases only from this two formula everything into the obl projecti motion is defined I will tell you by solving each and every question shall we shall we start everyone those who are live so you have to just remember these two formulas so you found a different approach or not everyone those who are like you found the different approach for the obl projectile motion or not right a particle is projected with the velocity V so that it range on the horizontal plane is twice of the height range is equal to twice Max height if G is accelerated due to gravity then range is what if you want to define the equation of range you all you all know the formulas now see R isal 4 H by tan Theta tan of theta that is equal 4 H by r r is twice of H Max 10an Theta we got it as 2 if we are following triangular method sin Theta will be 1 byot AR cos Theta will be 1 byun 5 sin Theta will be equivalent to 2 byun 5 okay so using this formula we found s cos tan and everything now what we need to find we need to find the range so R is equal to U cos Theta U sin Theta all divided by G so r is equal to U ² into 2 by 5G understood everyone and range is given as twice of Max height ah this is only the answer understood everyone there is a misprint into the option two should appear okay there is a misprint into the option sorry for that answer is 2 U S by 5G understood everyone answer is 2 U S by 5G okay this is given this is the formula we replace given data into the formula we got the angle this is the angle of projection this is the angle of projection uh last my formula sheet my formula sheet right don't get worried see this is the given data this is is the formula we replaced data into the formula we got the angle of projection if you want to find the range angle of projection is needed now see we found our angle of projection but in formula of the range we are having s and cos and we got answer in 10 so I use the trigonometry identity the fundamentals of the trigonometry from 10 I found s and cos right and I just replace into the formula of range understood everyone those who are live you can solve with the range formula also it's not a big deal but right you are going to reach onto the angle of projection only suppose if you're going to replace the range and height you are going to reach up to angle of projection only understood see projectile is thrown with the initial velocity what is the horizontal range see velocity Vector is given yes or no will be this is U cos Theta this is U sin Theta what is range u² sin Theta cos Theta my G right so it is 6 into 8 by 10 48 by 10 4.8 m is the range see velocity Vector is given or not everyone so question becomes easy or not question becomes easy or not everyone those who are live the maximum range of the gun see whenever this word is used in the maximum range it means projectile is fired as sptify whenever the maximum range word is used it means the projectile is fired at 45 and the range maximum always becomes angle of the projection always becomes 45 into the case of the maximum range and this becomes u s by 2G so you have to just replace 16 into 10 ^ 3 into 2 into 10 is = to u² 32 into 10 ^ 4 is = u² so can we get the muzzle velocity of the shell or not is it easy or not everyone those who are live are notes uh notes will be uploaded see there is one link given uh in below into the description there is one link right whenever you're going to click on that link now it will direct to you an app in that app all the notes will be available okay Santos Pam everyone those who are like the range of the horizontal projectile is okay this will be easy projectile is fired with velocity U at angle Theta if initial velocity is d range is directly proportional to sin 2 Theta or you can say range is as the angle of projection is same range is directly proportional to U Square okay nice lecture sir thanks thanks a lot R1 by I2 that is is equal to U1 s by U2 square right so it is 1x 4 so R2 that is is equal to 4 R1 understood is it easy or not everyone those who are live see this is important now I'm going to give you all the shortcut see these are the two equations of the trajectory of the projectile motion this are the two equations of the trajectory of the projectile motion right so if the equation is given they are telling us to calculate General maximum time the questions are asked from the second part only right so if I'm making 16x common right then it will be 1 - 5x by 64 16 x common 1 - x by 64x 5 if I'm comparing this to X tan Theta what is the range 64x 5 what is the range 64 by 5 no no no dpps is it easy or not everyone those who are live now it is important to discuss the shortcuts of the Riverman and Rainman problem right right there are two cases into the Riverman problem the first that is a shortest time and second case is the shortest distance you have to understand the concept logically once the rest is shortcuts lots of shortcuts are there here understood B everyone B is the width of the river in both of the cases the agenda would be remaining same we have to cross the river in both of the cases the agenda would remain same that we need to cross the river but here the agenda would be we need to cross the river in the shortest time and here in this case the agenda would be to cross the river with the shortest distance here the swimmer becomes stubborn here swimmer acts like smart 12th new badge announcement will be done soon so here what happens this is how river flows with respect to ground here in the both of the cases the shortcut is you always have to see the thing that appears to Observer on the ground is truth if you're going to stick on this statement right only The Observer on the ground can see the truth because he is on the ground and he becomes he becomes the inertial frame okay so this is is the velocity of the river with respect to Observer on the ground now here swimmer is standing what he thinks I want to cross the river I want to river cross the river but into the shortest time no matter at what point point I'm going to reach onto the opposite side doesn't matter my agenda is to cross the river into the shortest time because I'm scared of the water okay if I would reach at this point that point that I'm not interested what I would to do I will jump perpendicular to the river Santos things will be revealed here please focus on the concept right now what swimmer will do he will jump perpendicular to the river flow velocity of men with respect to River he blindly jump perpendicular to the river flow but slowly slowly slowly river is drifting he is swimming perpendicularly but a river drips he is swimming perpendicularly River drips so he thinks with respect to River he is going perpendicularly actually Rivers drips him and this truth is only seen by The Observer as of that reason this is the velocity of a man with respect to ground by this approach he reaches to to the opposite side but he is having the drift he reaches to the opposite side but our agenda was not to reach at the point B but instead of that our agenda was to reach onto the opposite side as of that reason he might have some drift now here the shortcut starts 10th Theta that is v r g BMR sin Theta p r g b mg cos Theta VMR vmg VG is d all divided by b d by under root of b² + d s b under root of b² + B okay so this is a shortcut this is the shortcut understood everyone those who are like this is the shortcut whatever the data it is given just pluck out that data and replace into the equation to get the answers right now suppose if you want to calculate the time of the journey if you are having the data of vmg right divided it by under root of B sare + D sare if you're having the data of VR G divided by drift if you're having the data of VMR divide by the width of the River from this equation directly you can calculate the time also suppose if you want to calculate the length of the journey this is the length from this direct formula based questions are going to come okay so this is the first shortcut of the shortest time understood everyone those who are like can have the answers into the comment box now swimmer things what swimmer thinks he want to start from point A only and want to reach exactly at the opposite point now he want to experience new things right now he want to experience new things so exactly want to starts from point A so this time what happened River was flowing into the same direction vrg this time what he thought he jumped at some angle with respect to the river flow in previous case he jumped perpendicular River drifted he swimmed perpendicular River drifted in this case what he did he jumped at angle River drifted he jumped and swimmed at some angle and River drifted like this way when he is inside the water he feels like he is moving at some angle but truth is seen by The Observer on the ground and he says the objetives the river is drifting the swimmer and he is traveling onto the straight path swimming onto the straight path right so this will be V mg again Theta this is the width of the river okay this was the drift that he was about to have tan Theta that is equal to V RG by V mg sin Theta that is equal to vrg all divided by VMR COS of theta that is is equal to V mg by VMR d by P D by under root of b² + D ² B by under root of B S plus b² again if you want to find the time of the journey if vrg is given have D okay if vmg is given have B if VMR is given under root of B S + D sare no question is going to come outside from this right Within 1 hour you will find the notes there will be a link into the description through that you'll be able to find the notes so I want to ask you all I want to ask the number of the students those who are watching this class live nothing extraordinary apart from this is going to come so do you find this shortcuts helpful or not everyone those who are live so this is the shortcut for the Riverman problem now that comes Rainman problem this is my sixth hour of today's live class see it's burning now I'm going to give you all the shortcut for the Rainman problem see Rainman problem you only have to follow the single approach what happens to the man when he is stationary what happens to the man when he's moving with the velocity when the man is stationary rain is falling vertically when he moves rain appears at some angle Theta so the shortcut lies in all of those cases you have to only calculate how rain appears to moving men in all of those cases you only have to calculate how rain appears to the moving man understood right let us take one example okay we will see this thing into the examples okay CH let's start rain drops are falling down vertically at four for a person moving forward at three see velocity of a man with respect to velocity of a rain with respect to man velocity of a rain with respect to ground velocity of a man with respect to ground rain is falling downward negative of 4J man is moving towards the right positive of 3 I so what is the velocity of rain with respect to man negative of 3 i - 4 J plot this on the graph -3 I -4 J this is how rain appears to moving men against to do this he has to hold the umbrella understood everyone so in all of the case is you have to calculate what how rain appears to moving man how rain appears to moving men how rain appears to the moving man answer is five you have to find the magnitude of it this is one and the same a man want to cross the river 600 M wide flowing see he want to cross the river into the shortest time direct data is given if it is given shortest time directly go on to the shortcut of the shortest time apply the formula get the answers what is the path length covered C shortest time can we use this formula see width is given River velocity see V RG by V mg is equal to or you can say you can use this equation also because we need to find the length we need to find this vector vector okay VMR by V mg is equal to B by under root of b² + D ² instead of that you can use length replace values get the answer replace values get the answer understood everyone those who are live so are this shortcuts helping or not person can move in still water at five River moves with three shortest distance what is the time are sorry this is the case of upstream and downstream sorry okay upstream and downstream sorry hold on this we can Sol it by yourself some questions I have kept for you all to practice some questions I have kept you all for practice into the notes that will be available into the notes and we are limiting the session up to year only okay because uh extending the session Beyond this right it will be like Injustice with you all your eyes will get strained and everything right so this much is enough tomorrow we are going to come back with the Newton's law of motion and we are going to solve more than 50 sums into the sessions right understood Suk say Su we did that now we did that now you can see the explanation direct shortcut we used right are in this neat right the topics what we have discussed in the neat this is a shortcut of shortest time in shortest time he swims perpendicular to the river but River drifts in case of shortest distance he swims at the angle and River drifts him straight okay upstream and downstream okay upstream and downstream while moving up stream we are going against the river so time is calculated as Downstream right velocity of river and velocity of boat so time will be V r + VB by distance the approach of plus and minus is only there Upstream we are going against to the river Downstream we are going with the river so when you go Downstream velocities with the river are added when you go Upstream velocity to the rivers are subtracted because we are moving into the opposite direction okay if all students feel that you you found something good if your knowledge has been enhanced before and after this session right please write down one comments beneath the box right please write down the comments beneath the box right if you like this sessions it is really fruitful right tomorrow we will start with the nlm right okay guys so that much is enough for today this is your own physics educator indrajit Singh right signing off from the desk bye-bye I'll will be waiting for all all of your your right comment okay beneath the video so this is your own physics educator indrajit Singh signing off from the desk bye-bye satal and Namaste from my side bye everyone stay at home stay safe stay healthy prepare well for the 2024 bye