types of waves hello friends so today I am going to introduce to you a very interesting topic types of waves in a last module we've discussed about a wave so how do you describe a wave a wave can be described as a different as a disturbance that travels through a medium from one location to another the doubt transporting any matter that's enough that's a point to ponder without transporting any matter do you know what a mechanical wave is here I'm going to give you a brief introduction about a mechanical wave and the detailed information I share with you in my next module okay so a mechanical wave is nothing more than a disturbance which is traveling through a medium such as a solid liquid or a gas as you see in the case of water waves that are formed when I throw a stone into the lake or a pond that's as simple as that as a mechanical wave now this disturbance so created in the lake is caused due to the to and fro motion of the water particles so now in this module we are going to discuss about the various types of waves like in a previous module we have taken a situation where a group of people was standing in a queue and all of them was holding each other through their shoulders so what did he observe were there what was actually happening over there when one person sits down he pulls his neighboring person to sit down as well and when he stands up he again pulls his neighboring person to stand up so it keeps on moving that way so each person here is undergoing only up and down motion and this disturbance is propagated towards the last person of the group similarly we can take an example of a rope so if I have a rope with me you can see here the disturbance it travels through the rope and how this is traveling through the rope let's see what do you see if you carefully observe this rope yes if you carefully observe this road then you must have noticed that the red dots these the red dots which are present of the room they keep on undergoing to and fro motion about their mean position while the disturbance it isn't travelling forward through the rope so what do you conclude from the above two examples so it is concluded that it is the disturbance that is carried forward but the particles of the medium they are undergoing to and fro motion only and that is about the mean position so he'll veins they move straight from one end to the other end while the particle motion which makes that particular wave is in the direction which is perpendicular to the direction of propagation of the wave now this type of wave is called as any guesses yes this type of wave is called as the transverse wave in which the particles of the medium they move in a direction which is perpendicular to the direction of propagation of wave and some of the examples of transverse waves are the water waves which are formed when I drop a stone into a lake or a pond the light waves and the radio waves these are all examples of transverse waves now let's do a simple activity to demonstrate how a transverse wave looks like let's take a slinky and place it on the table and we're fixing its one end and the other end is let free now I hold the free end of the slinky and just to whip it what do we observe the slinky it appears to move like a snake and it shows a wavy appearance what kind of wave does this vibrating slinky represent here yes we've started this and it's a transverse wave a transverse wave in which the particles undergo to and fro motion about their mean position and moves in a direction which is perpendicular to the direction of wave propagation now we'll take some the same group of people that we had taken earlier but this time with a slightly different arrangement and let's see what happens so it is the same group of people but in this case they are not holding each other through the shoulders or through their elbows now in this case the first person he gently pushes the second person sideways and then pulls them back you see this push and pull moment and this is propagated towards the last person of the group so how is this moment different from the previous one if each person is holding each other through their shoulders that's something which we have to look forward to you can see here in the previous case each person was undoing up-and-down motion while in this case each person is moving back and forth back and forth about their position and the push and pull is transmitted to the person at the end now consider the case of slinky who's one end is fixed to a point what happens now I give it a push to it and what do we observe yes you observe that some sort of disturbance is carried forward from one end of the slinky to the other end what is this disturbance this disturbance is carried forward while all the rings of the slinky are moving back and forth back and forth about the mean position but the disturbance and gets carried forward now if i push the slinky forward and backward forward and backward continuously then what do you see it's another interesting thing that we observe you see here a series of compressions followed by reflections compressions and rarefactions that the compressions are the regions where the Rings are crowded together and rare fractions are the regions where the Rings are far apart so compression and rarefaction both move forward and in this case wave motion is in one direction and the motion of particles of the medium are in a direction which is parallel to the direction of propagation of the wave now what do we call this kind of wave this presents us the second kind of wave which is known as the longitudinal wave in which the particles of the medium they undergo back and forth motion about the mean position and this is parallel to the direction of propagation of wave and some of the examples of longitudinal waves are the sound waves when I'm speaking the sound wave which I emerge from my mouth is an example of this longitudinal wave so let's summarize till now whatever we have studied we've studied that there are two types of waves a transverse wave and a longitudinal wave a transverse wave in which the particles of the medium move in one direction which is perpendicular to the direction of wave propagation and they oscillate about the mean position to end flow motion the examples were a ripple on the pond or a lake and a veil on the string they can be easily visualized as transverse waves some of the other examples that we studied about were the light waves the heat waves and radio waves all are examples of transverse waves now coming to the longitudinal waves the second kind of waves in which the particles of the medium they move in a direction which is parallel to the direction of wave propagation and we had the examples of sound wave of sound waves a wave in a slinky so these are good visualizations of longitudinal waves so this is all about the types of waves and in our next module we'll discuss about sound waves in detail