in this video we'll talk about two objects onto a double inclined plane so we have a car on an inclined plane which is connected to a mass on the other side on the other inclined plane and the goal is to make this object or this car descend at a constant speed and we also applying the brake onto the car as well so we need to find out what is the braking average braking force to make this car decent at a constant speed okay so let's do it we call this as a theta so the given value are this mass is 1700 kilogram and this mass which is connected to the car is 1500 kilogram angle is 30 degree and this is 20 degree we call this angle theta and this angle alpha before we solve this problem or if we talk about anything first thing we need to do is draw the free body diagram so let's draw the free body diagram so we have the card here the weight on of the card is vertically downward the gravity force is always downward m1 g and we're going to resolve this into two components the one parallel to the inclined plane and the other perpendicular to the inclined plane the as this angle is theta this angle will also be the theta so perpendicular to the component as this angle is theta will be m1g cosine theta and parallel to the inclined plane it will be m1g sine theta and the other force that is acting under the car is the normal force the normal force is always perpendicular to the surface and as we applying the brake brake onto the car the braking force is also opposite to the motion which is along this way the braking force so the so we have resolved all the forces here draw the in this free body diagram let's draw the free body diagram of the mass as well exactly the same process exactly the same process the first thing is the the weight the weight is downward which is m2g and again this angle is alpha so is this angle also alpha and this component will be m2g cosine alpha and parallel to the surface would be m2g sine alpha and we do not need this force anymore because we already have dissolved this into two components and the normal force is now n2 onto the surface we do not know n2 our goal is to make this descend at a constant speed so we need to write down all the forces acting onto the car onto this car here so what are the total forces acting onto the car along the direction of the inclined plane so the first force is m1 g sine theta which is acting downwards on the slope this force and the second force is f b which is the breaking force and there is an additional force which is coming from this mass here this mass is also trying to pull the uh the car or this one is just stopping or helping to descend the car at a constant speed or is another force so what is the force here this force this for this car is connected to the mass by this string here by this rope here and along this direction this is m2g sine alpha so the force acting onto the car or a log in this direction is m 2 g sine alpha so this is along this direction so the total force on to the car is m 1 g sine theta minus the breaking force and minus m2 g sine alpha the negative sign for these two because these two are in opposite direction okay so this is this is the total force now and now as the car is descending at a constant speed the acceleration of the car is zero the acceleration means the change in this velocity and as the car is moving in a straight line with a constant speed and the acceleration is zero so now by newton's second law of motion the force is equal to mass times acceleration and the acceleration is zero and now what is the total force the total force is right here m1g sine theta breaking force and to g sine alpha and we are interested in solving fb so the breaking force is now m1g sine theta minus m2g sine alpha so let's plug in all the values the mass f1 is given which is 1700 g values is 9.8 theta is 30 degree m2 this mass is 1500 9.8 sine 20 degree so the breaking force that is required to make it to move at a or descent at a constant speed is 3300 newton okay so that's it from this video again if you have any questions write down your question in the comment section below and do not forget to like share and subscribe the video thank you so much