The bounce of a squash ball Essay Example for Free

The bounce of a squash ball Essay Then the ball will soon begin to lose speed as it rises and its KE (kinetic energy) is changed back to GPE (gravitational potential energy)as some of its original energy has been converted to heat and sound it will stop with less GPE (gravitational potential energy) than it began with. This is the reason why the height of the bounce for all the temperatures is lower than the original height (1 meter). Conclusion: You can understand from the evidence that my prediction was right as the higher the temperature of the squash ball, the higher the height of the bounce will be. As you can understand from the results the lowest temperature of 0i C gave an average bounce height of only 5m which would be 5% of its initial height. On the other hand the highest temperature of 70i C gave an average bounce height of 58. 4m which is 58. 4% of its original height. This proves my prediction right as not only can you see from the results that the bounce height increases as the temperature increases, you can then see from these results that it must be due to the gas inside the ball heating up, causing the volume of the gas to expand and the molecules to move faster which will caused them to hit the sides more often and harder. This made the rubber expand and store more elastic energy. This meant that the bounce height was bigger because the more stretched the rubber became, the better it converted elastic potential energy into kinetic energy when the ball hit the floor and therefore caused the ball to bounce higher. Evaluation I think that my results were as accurate as I could have made them with relevant safety points carried out and I got good, reliable, accurate results. The only anomaly I got was at 10i C because the temperature kept dropping which made the average too low. I decided to do the test for 10i C again and my results were much better. The average result for 70i C was lower than the line of best fit because I think that once the ball starts to reach the higher temperatures the ball cant keep on stretching and eventually it will reach its maximum stretch and therefore it wont bounce any higher, it will level out. The 70i C point looks like it would be the start of a curve to the levelling out of the bounce height. Other than that my results are very accurate as they are all very close to my line of best fit suggesting that there arent any anomalies although some points are further away from my line of best fit than others. These arent anomalies though because not every point will be exactly on the line of best fit because it would have to be extremely well controlled and that isnt possible in classrooms and unlikely to be possible in the most controlled laboratories. There will always be differences in the results no matter what so therefore I believe that my results were as accurate as possible. My investigation could have been improved by: i Not doing the test over two lessons so all of the equipment would be the same. i Making sure that all the preliminary work was done before I did the actual experiment. i Making sure the temperature was kept exactly the same and not letting it drop or increase by even 1i C. i Doing more tests to make sure I get a very accurate average. i Being quicker between taking the ball out of the water bath and dropping i Not allowing the squash ball to some to the surface of the water bath at some points, keep it below the surface to make sure it definitely reaches thermal equilibrium. I think my results were very reliable even though it was done over two lessons so some of the equipment wasnt the same but it wouldnt have made much difference as all the equipment was mostly the same and were all accurate. At the lower temperatures such as 0i C and 10i C it was hard to keep the temperatures down in a warm room and had increased by a degree or two which could have made a difference to the bounce height. This would explain why the 10i C point was higher than the line of best fit. Other than that we were very accurate with keeping the water bath at the right temperature and this was shown by the closeness of the points to the line of best fit. To provide additional relevant evidence I could: i Use temperatures that go up in 5i C instead of 10i C so I would have more information to show the relationship between the temperature of a squash ball and its bounce height. i I could have a better way of seeing the bounce height by having a video camera set up about a metre away from the experiment to see where about the ball bounced and then have another camera close up to see a closer reading of the bounce height. When I play back the video, I would put it on slow motion and show it frame by frame recording the heights until the bounce heights start to fall. Then I would take the maximum recording I had for that temperature and that would be the bounce height. This would be very accurate because I would see a very close up measurement and because it would be in slow motion and frame by frame it clearly showed the bounce height and could clearly be read from the bottom of the ball. This is more accurate than using your eyes because the ball would bounce very quickly and you only have a split second to read the height and is very difficult.