coefficient of restitution || 11th physics practical #11thphysics @a2zpractical991

Hello friends and welcome to my channel. So friends, I am Sachin Shukla and you are watching A to Z Practical. So, friends, today's practical is basically an activity. Today I am going to start activity number 4, which is the coefficient of restitution. So let's start the experiment quickly. But friends, let me tell you, I've uploaded all the practicals for grades 11 and 12. Go take a look. I have explained very good practicals to you. And definitely support this channel. Thank you, and let me show you the experiment. This is activity number 4, coefficient of restitution. So basically, we have carried out this experiment. So let me tell you quickly. Friends, you can see the mass of the ball here. So, friends, this is a weighing machine, and I have 3 balls. I need to determine the mass of M1, M2, and M3. So first I take this red ball. And let me see its mass. So I keep it here. Its mass is 100 grams. What is the mass of the first ball? And let's see the mass of the second ball. So the mass of the second ball is 70.2 grams. And the mass of the third ball is 9.8 grams. So I have calculated the mass of all three balls. So the mass of M1 is 100 grams. And the mass of the second ball is 70.2 grams. And the mass of the third ball is 9.8 grams. So, friends, I have taken a strip of 100 cm. And I have three balls of different masses. So the initial height of the ball is written there. So what you have to do is that I will start from 100. So the initial height will be 100. So we have balls of three different masses. And we have to conduct two types of experiments here. Two types of experiments mean, One is the surface of the ground, and the other is the surface of wood. So let's see how high the ball bounces. So as soon as the first bounce falls, And how many centimeters does the first bounce reach, We have to measure it. So you must experiment very carefully. So let's begin the experiment. I have three balls here. So the ball of heavy mass, I will drop it from 100 cm. And as soon as I drop it from 100 cm, It will bounce back. And we must write down the first reading. So, friends, I'll drop it from 100 meters. And I will see where the first rebound will occur. So I leave it here. I have to drop it from 100 cm. So where is it coming from? It is basically 74. It is clear that its mass is slightly less. So let's get rid of it from here and see how much comes back. Friends, it's coming up to 56. And third, we have a plastic ball. Let's throw it and see how high the first bounce is. It's approaching 51. So, friends, now there's another one here. You have to take a wooden block. You have to bounce this ball on that wooden block. And as soon as it bounces back from the wood, You must write down the same reading. So you have to take this wooden block. And you must bounce the ball from a height of 100 cm onto it. And as soon as it bounces back anywhere, You must note down that reading. So first, I have a high weight. So I bounce back the red ball. Let's see how much reading it entails. So here I will bounce it back from 100 cm. So now let's see how much it gives on wood. It's going up to 66. Let's see how much it comes to. Let's drop it from 100. It's coming to 50. And let's see how much it's coming to. It is coming 54. Sorry, it's coming to 44. It's coming 44. It came 54. And how much did it cost? It reached 66. What's happening on Wood is that it's coming in a bit less. The initial height of the ball. So from what height were we throwing the ball? So we are basically from 100 cm. The height of the ball's bounce from the rigid floor of the surfaces. Means when you were bouncing the ball off the surface. So after the rebound, where was it heading at the first peak? It was going at 74. Where was it going? At 74 cm. After that, when we did it from the second ball. Whose 70-gram weight is there? So there we were, getting 56 cm. And when we did it from the third plastic ball. So there we have 51 cm. Second place I had kept the wooden surface. Clear. So for the wooden surface, the first bounce of the ball was at 66. The second one was at 54. And where was the third ball at? At 44. Okay. Now let's look further. Calculation of the coefficient of restitution. How much was the first ball of 1? So what do you have to do? E is equal to h2 divided by h1. So how do you have to calculate E? How much was your H2? You can see here. How much is your H2 here? 74 cm Okay. You have to divide 74 by h1. How much is your H1? 100 cm Okay. So you have to divide 74 by 100. So what do you have to do? 0.74 So you have to divide this. And whatever answer you get, you must find its square root. So you will get the value 0.86. So how much will be here? 0.86 Same. You will do the same for the second one. For the second one, you can see here. Your second reading is 56. You can see here. How much is your reading? 56 You will divide 56 by 100. You will divide 51 by 100. Same. You have to do the same for wood. So what have I done? If I divide it again, I'll get 0.74. If you do this, you will get 0.71. After this, you must do the same for the wooden surface. You have to perform root H2 by H1. How much is your H2? You can see here. 66 How much is your H2 here? How much is your H2? 66 So you have to divide 66 by 100 again. So you will divide 66 by 100. So you will get 0.81. Same. Divide the second reading by 100. And divide the third reading by 100. So you will get this. Okay. If you like this video, please subscribe to this channel. So that I can get motivated to create many videos for you. Thank you.