An Investigation into the factors of what affects the height at which a dropped squash ball bounces

The energy involved in an object falling is called potential energy. It can be calculated by using the formula: Potential Energy= Mass x N/Kg (this is gravity) x Height.

As the object falls the Potential energy is transferred into Kinetic Energy (movement). When the ball hit's the ground the energy is transferred into elastic energy, however some of this energy is lost as sound and heat energy, hence the fact the bounce is shorter each time.

On earth the gravity is 10N/Kg this is because for every kilogram 10 newtons is exerted upon it by the pull of the earth's rotation.

Experiment Plan

I plan to set up the apparatus with a 2 meter rules to measure the bounce height, and I intend to measure the bounce height with the eye.

This isn't the most accurate methods of doing this experiment but I did not have the resources to calculate the bounce height using another method.

The other methods I could have used were computer generated programs where I input the data like drop height, floor surface, ball temperature etc. but I did not have the necessary program. I shall try to perform the experiment quickly so the temperature of the ball does not vary too much. Also I shall keep the experiment in one location so the floor surface is constant throughout the experiment.

Hypothesis

I predict that the higher the ball is dropped from the higher it will bounce because there will be more energy stored in it so when it hit's the ground there will be a greater release.

Obtaining evidence

I carried out the experiment as described above and these were te result I recorded, I did the experiment 3 time so an average could be worked out hich would reduce the chances of an error in the results.

Drop Height (cm)

Bounce height experiment 1

Bounce height experiment 2

Bounce height experiment 3

Average Bounce

25

0

8

9

9

50

6

6

5

5.6

75

20

22

23

21.6

00

28

32

28

28

25

30

31

30

30.3

50

38

36

37

37

75

47

46

44

45.6

200

52

52

53

52.3

The outcome was what I predicted because as shown the higher the ball was dropped the higher it bounced. There is only 1 anomaly which was in experiment 2 from a height of 100 cm this one doesn't seem to be correct because the next distance up produced a smaller bounce height.

Analysing Data

As shown in the data the higher the ball was dropped from the higher it bounced. This is because the higher it was dropped from the more energy would have been transferred to it in the form of potential energy, and when it was released it would have more time to accelerate, so when it hit the ground as there was little potential energy left it would have been transferred to kinetic enrgy in the form of a bounce.

There was only one item of data which I thought was biased and I highlighted it in bold and italics. I thought this was incorrect because it is a lot higher than the other two results from the same height and also it was higher than all the drops from the next height, which suggests that the height may have been read wrong. I have decided to omit this particular piece of evidence from my results and but still use it in the average.

As shown on the graph there is a clear trend line going up and as the drop height increases the bounce height increases as well which was exactly what I predicted.

However I was expecting the graph to be slightly curved as the higher it dropped the more energy it would gain. However I am assuming that I either did not do enough points to show this curve or I did not drop it from high enough heights to make a significant difference in the energy.

On the graph there are four lines which are all mainly centred around the average line, which shows that the results were accurate. There was only 1 major outlier and that was the point which I mentioned above and I circled it to make it stand out.

The graph appeared to run on a straight line apart from in the part where it is slightly bowed. If I had drawn the line of best fit to encompass this then the line would not have resembled either a curve or a straight line, so I assumed that it was just that he results were slightly wrong.

Also the average line is not perfectly drawn however this is entirely human error, not an error in the results.

Conclusion

In conclusion I have determined that the higher the squash ball is dropped from the higher it will bounce this is because it will have gained more potential energy as it was lifted therefore as it falls it will be transferred into kinetic energy and when it hit's the ground as it has been travelling faster there will be a greater force which compresses the ball and then the elasticity of the material will send it back up.

Overall I feel the experiment went well. If I were to do the experiment again I would certainly use larger drop heights, maybe measured in meters as this would really show if the graph of results was curved or not. Also I would use a more accurate way of measuring the bounce height, as I feel that the way that I used was not accurate enough.

Also I would have like to have drawn the graph again however I was unable to as I only had one piece of graph paper.

All in all I am pleased because the experiment went well, there were few errors and it was an interesting investigation.