The Efficiency Of Bouncing Balls

Updated on October 15, 2015

Aim / Purpose ~

My aim of this investigation is to find out the efficiency of a golf ball, netball, ping pong ball, rubber ball, tennis ball and a baseball on their first bounce from a 90cm high drop.

Hypothesis ~

If the ball is bigger in mass, then the ball will have a lower rebound bounce, meaning a lower efficiency, because the kinetic energy that turns into gravitational energy once the ball hits the ground will not be able to push the ball up as high than a ball with lesser mass.

Equipment / Materials ~

• 1x 1 metreruler
• 1x Golf ball
• 1x Netball
• 1x Ping Pong ball
• 1x Rubber ball
• 1x Tennis ball
• 1x Baseball
• 1x Flat floor
• 1x Counter top approximately 85cm high
• 1x IPad or other recording device
• 1x Pencil or pen
• 1x Calculator
• 2x Nail size pieces of blu tack
• 1x Assignment Booklet

Independent Variable
Dependent Variables
Controlled Variables
The type of ball.
The rebound height of each ball.
Initial drop height (90cm).

The efficiency of each type of ball.
Force

Ruler

Pen / Pencil

Calculator

Blu Tack

Assignment Booklet

Floor

Counter

Discussion Questions ~

1. Identify The Sources Of Energy Input For This Experiment.

The sources of energy input for this experiment are gravitational potential energy and heat energy. Gravitation potential energy because the ball is above the ground, and heat energy because of the human touching the ball transfers their body heat to the ball.

2. Identify The Types Of Energy Produced.

The types of energy that are produced are kinetic energy, elastic potential energy, sound energy, heat energy, and then once again gravitational potential energy. Kinetic energy because the ball transfers gravitational potential energy into kinetic energy as it falls. Elastic potential energy because when the ball hits the ground, the shape changes and causes elastic potential energy. Then as the shape is restored, the elastic potential energy changes back into kinetic energy. Once again gravitational potential energy because as the ball gets higher in the air, the kinetic energy is transferred back into gravitational energy. Sound energy because when the ball hits the ground, the vibrating body causes the medium around it to vibrate causing sound. Lastly heat energy because when the ball hits the ground and deforms, it rubs against the floor and causes friction, which then causes heat.

3. Define The Term Energy Efficiency.

Energy efficiency is the proportion of useful energy output from a device compared to the amount of energy that is input. This is usually expressed as a percentage.

Another definition is that energy efficiency is a way of managing and restraining the growth in energy consumption. Something is more energy efficient if it delivers more services for the same energy input or the same services for less energy input.

For example, when you replace an appliance, such as a refrigerator or clothes washer, or office equipment, such as a computer or printer, with a more energy-efficient model, the new equipment provides the same service, but uses less energy. This saves you money on your energy bill, and reduces the amount of greenhouse gases going into the atmosphere.

4. List The Forms Of Wasted Energy, If Any That Are Produced In This Experiment.

The forms of wasted energy in this experiment are heat energy and sound energy. Heat energy because the heat is not being used, and sound energy because the sound is not being used.

5. Propose Ways To Improve Your Experiment Design.

Some ways I believe I could improve my experiment design is by:

• Using a higher megapixel recording device, so I can see the measurements on the ruler clearer and more accurately.
• Make the same group member drop all the balls, as some people drop objects differently.
• Hold the balls for the same period of time, as human heat transfer to the balls can effect the efficiency of them, making the test not a accurate.

6. Propose Reasons Why The Balls Varied In Efficiency.

I propose that the balls varied in efficiency because they all were different masses and mass effects the efficiency of an object. If an object is heavier it adds more weight, which causes more friction and more friction means less efficiency, but if it is lighter, it causes less friction and means a higher efficiency.

Another reason I propose is that because they are all made of different materials. Different materials conduct heat from friction, cause friction and produce sound differently, meaning that the balls could be of a higher or lower efficiency depending on their material.

Procedure ~

1. Set up the equipment in an appropriate manner.
2. Get the IPad ready to record by turning the device on, swiping the lock screen and clicking on camera and swapping it to recording mode, then press record.
3. Whilst the IPad is recording grab and drop, do not push the golf ball from in front of the ruler at 90cm.
4. Press stop on the recording screen.
5. Watch the video of the dropping golf ball.
6. Observe the height of the 1st rebound height of the golf ball.
7. Record this result in your assignment book under trial 1 for the golf ball.
8. Make sure the IPad is still ready to record and press record.
9. Whilst the IPad is recording grab and drop, do not push the golf ball from in front of the ruler at 90cm.
10. Press stop on the recording screen.
11. Watch the video of the dropping golf ball.
12. Observe the height of the 1st rebound height of the golf ball.
13. Record this result in your assignment book under trial 2 for the golf ball.
14. Make sure the IPad is still ready to record and press record.
15. Whilst the IPad is recording grab and drop, do not push the golf ball from in front of the ruler at 90cm.
16. Press stop on the recording screen.
17. Watch the video of the dropping golf ball.
18. Observe the height of the 1st rebound height of the golf ball.
19. Record this result in your assignment book under trial 3 for the golf ball.
20. Now work out the average of the golf ball rebound height by adding all of the measurements for the golf ball up rebound height and then dividing the answer by 3.
21. Record this answer in your assignment book under the golf ball average.
22. Now work out the efficiency of the golf ball by dividing the average rebound height of the golf ball by the initial drop height (90cm), then times this by 100%.
23. Record this answer in your assignment book under the efficiency for the golf ball.
24. Make sure the IPad is still ready to record and press record.
25. Whilst the IPad is recording grab and drop, do not push the ping pong ball from in front of the ruler at 90cm.
26. Press stop on the recording screen.
27. Watch the video of the dropping ping pong ball.
28. Observe the height of the 1st rebound height of the ping pong ball.
29. Record this result in your assignment book under trial 1 for the ping pong ball.
30. Make sure the IPad is still ready to record and press record.
31. Whilst the IPad is recording grab and drop, do not push the ping pong ball from in front of the ruler at 90cm.
32. Press stop on the recording screen.
33. Watch the video of the dropping ping pong ball.
34. Observe the height of the 1st rebound height of the ping pong ball.
35. Record this result in your assignment book under trial 2 for the ping pong ball.
36. Make sure the IPad is still ready to record and press record.
37. Whilst the IPad is recording grab and drop, do not push the ping pong ball from in front of the ruler at 90cm.
38. Press stop on the recording screen.
39. Watch the video of the dropping ping pong ball.
40. Observe the height of the 1st rebound height of the ping pong ball.
41. Record this result in your assignment book under trial 3 for the ping pong ball.
42. Now work out the average of the ping pong ball rebound height by adding all of the measurements for the ping pong ball rebound height up and then dividing the answer by 3.
43. Record this answer in your assignment book under the ping pong ball average.
44. Now work out the efficiency of the ping pong ball by dividing the average rebound height of the ping pong ball by the initial drop height (90cm), then times this by 100%.
45. Record this answer in your assignment book under the efficiency for the ping pong ball.
46. Make sure the IPad is still ready to record and press record.
47. Whilst the IPad is recording grab and drop, do not push the tennis ball from in front of the ruler at 90cm.
48. Press stop on the recording screen.
49. Watch the video of the dropping tennis ball.
50. Observe the height of the 1st rebound height of the tennis ball.
51. Record this result in your assignment book under trial 1 for the tennis ball.
52. Make sure the IPad is still ready to record and press record.
53. Whilst the IPad is recording grab and drop, do not push the tennis ball from in front of the ruler at 90cm.
54. Press stop on the recording screen.
55. Watch the video of the dropping tennis ball.
56. Observe the height of the 1st rebound height of the tennis ball.
57. Record this result in your assignment book under trial 2 for the tennis ball.
58. Make sure the IPad is still ready to record and press record.
59. Whilst the IPad is recording grab and drop, do not push the tennis ball from in front of the ruler at 90cm.
60. Press stop on the recording screen.
61. Watch the video of the dropping tennis ball.
62. Observe the height of the 1st rebound height of the tennis ball.
63. Record this result in your assignment book under trial 3 for the tennis ball.
64. Now work out the average of the tennis ball rebound height by adding all of the measurements for the tennis ball rebound height up and then dividing the answer by 3.
65. Record this answer in your assignment book under the tennis ball average.
66. Now work out the efficiency of the tennis ball by dividing the average rebound height of the tennis ball by the initial drop height (90cm), then times this by 100%.
67. Record this answer in your assignment book under the efficiency for the tennis ball.
68. Make sure the IPad is still ready to record and press record.
69. Whilst the IPad is recording grab and drop, do not push the rubber ball from in front of the ruler at 90cm.
70. Press stop on the recording screen.
71. Watch the video of the dropping rubber ball.
72. Observe the height of the 1st rebound height of the rubber ball.
73. Record this result in your assignment book under trial 1 for the rubber ball.
74. Make sure the IPad is still ready to record and press record.
75. Whilst the IPad is recording grab and drop, do not push the rubber ball from in front of the ruler at 90cm.
76. Press stop on the recording screen.
77. Watch the video of the dropping rubber ball.
78. Observe the height of the 1st rebound height of the rubber ball.
79. Record this result in your assignment book under trial 2 for the rubber ball.
80. Make sure the IPad is still ready to record and press record.
81. Whilst the IPad is recording grab and drop, do not push the rubber ball from in front of the ruler at 90cm.
82. Press stop on the recording screen.
83. Watch the video of the dropping rubber ball.
84. Observe the height of the 1st rebound height of the rubber ball.
85. Record this result in your assignment book under trial 3 for the rubber ball.
86. Now work out the average of the rubber ball rebound height by adding all of the measurements for the rubber ball rebound height up and then dividing the answer by 3.
87. Record this answer in your assignment book under the rubber ball average.
88. Now work out the efficiency of the rubber ball by dividing the average rebound height of the rubber ball by the initial drop height (90cm), then times this by 100%.
89. Record this answer in your assignment book under the efficiency for the rubber ball.
90. Make sure the IPad is still ready to record and press record.
91. Whilst the IPad is recording grab and drop, do not push the netball from in front of the ruler at 90cm.
92. Press stop on the recording screen.
93. Watch the video of the dropping netball.
94. Observe the height of the 1st rebound height of the netball.
95. Record this result in your assignment book under trial 1 for the netball.
96. Make sure the IPad is still ready to record and press record.
97. Whilst the IPad is recording grab and drop, do not push the netball from in front of the ruler at 90cm.
98. Press stop on the recording screen.
99. Watch the video of the dropping netball.
100. Observe the height of the 1st rebound height of the netball.
101. Record this result in your assignment book under trial 2 for the netball.
102. Make sure the IPad is still ready to record and press record.
103. Whilst the IPad is recording grab and drop, do not push the netball from in front of the ruler at 90cm.
104. Press stop on the recording screen.
105. Watch the video of the dropping netball.
106. Observe the height of the 1st rebound height of the netball.
107. Record this result in your assignment book under trial 3 for the netball.
108. Now work out the average of the netball rebound height by adding all of the measurements for the netball rebound height up and then dividing the answer by 3.
109. Record this answer in your assignment book under the netball average.
110. Now work out the efficiency of the netball by dividing the average rebound height of the netball by the initial drop height (90cm), then times this by 100%.
111. Record this answer in your assignment book under the efficiency for the netball.
112. Make sure the IPad is still ready to record and press record.
113. Whilst the IPad is recording grab and drop, do not push the netball from in front of the ruler at 90cm.
114. Press stop on the recording screen.
115. Watch the video of the dropping baseball.
116. Observe the height of the 1st rebound height of the baseball.
117. Record this result in your assignment book under trial 1 for the baseball.
118. Make sure the IPad is still ready to record and press record.
119. Whilst the IPad is recording grab and drop, do not push the baseball from in front of the ruler at 90cm.
120. Press stop on the recording screen.
121. Watch the video of the dropping baseball.
122. Observe the height of the 1st rebound height of the baseball.
123. Record this result in your assignment book under trial 2 for the baseball.
124. Make sure the IPad is still ready to record and press record.
125. Whilst the IPad is recording grab and drop, do not push the baseball from in front of the ruler at 90cm.
126. Press stop on the recording screen.
127. Watch the video of the dropping baseball.
128. Observe the height of the 1st rebound height of the baseball.
129. Record this result in your assignment book under trial 3 for the baseball.
130. Now work out the average of the baseball rebound height by adding all of the measurements for the baseball rebound height up and then dividing the answer by 3.
131. Record this answer in your assignment book under the baseball average.
132. Now work out the efficiency of the baseball by dividing the average rebound height of the baseball by the initial drop height (90cm), then times this by 100%.
133. Record this answer in your assignment book under the efficiency for the baseball.
134. Return all of the equipment and dispose of any rubbish safely.
135. You have now completed the experiment.

Evaluation ~

My results show that the ping pong ball had the highest average rebound height (59cm) and efficiency (66%), followed by the netball with the average rebound height of 54cm and the efficiency of 60%, followed by the tennis ball with the average rebound height of 41cm and the efficiency of 46%, followed by the baseball with the average rebound height of 40cm and the efficiency of 44%, followed by the rubber ball with a rebound height of 24cm and the efficiency of 27%, then in last place, the golf ball with a low rebound height of 23cm and the efficiency height of 26%. These results are shown in my results table and graph.

My results suggest this happened because in energy terms, the more efficient the ball is at converting kinetic energy to elastic potential energy and back to kinetic, the better it will bounce and less energy is lost. So my results are further suggesting that the ping pong ball is better at converting kinetic energy to elastic potential energy and vice versa. Then the netball, then the tennis ball, then the baseball, then the rubber ball, then lastly the golfball.

All of the data from my table and graph can be used to explain what happened because my table shows the heights of the rebounds of each of the ball, the average of the rebounds and also the efficiency. My graph also shows the efficiency of each of the balls. So as I have previously stated all of my data from my table and graph can be used to explain what happened because they (especially the table) go through what happened throughout the experiment, showing basically step by step what happened.

I can see a pattern in my results, which is shown in my results table. Each specific balls measurements of their rebound are all very close together in size meaning that the specific ball that is dropped will generally (with some exceptions) have roughly the same rebound height and efficiency. One smaller pattern I can see is that the efficiency is very similar in numbers to the average rebound height of each of the balls. Once again this is shown in my results table and graph and are proven.

A possible explanation for these patterns could be that the same ball generally has the same rebound height because, as I said it is the same ball. Meaning the same material, type of friction, etc. So this explains why the type of ball has very similar measurement for each rebound height. For the second pattern of similar sized efficiency to average rebound height is just a coincidence and how it just seems to appear. But the other pattern of the same ball having basically the same rebound height size is because it is the same ball. These results are all shown in my results table and graph and are proven.

My results in my results table and graph do not prove my hypothesis nor disprove. But it is mostly false. My hypothesis was “If the ball is bigger in mass, then the ball will have a lower rebound bounce, meaning a lower efficiency, because the kinetic energy that turns into gravitational energy once the ball hits the ground will not be able to push the ball up as high than a ball with lesser mass.” It is not proven because some of the heavier balls did have a higher efficiency and a higher rebound height, than some of the balls with a lower mass. But it is not disproved completely because the lightest ball, the ping pong ball, was the ball with the highest efficiency and rebound height. Let me further show you evidence of results linked to my hypothesis. These are the balls that were used and are in order from most efficient to least. This also states their mass. Ping pong ball = 2.7gm, Netball = 450gm, Tennis ball = 59gm, Baseball = 145gm, Rubber ball = 240gm and Golf ball = 45gm. So in the end my hypothesis is not fully correct but, so yes disproven, but the only wrong things are the netball and golf ball. The rest are in order of lightest mass to heaviest mass. I believe the netball and golf ball do not follow this because of their material. So from this I have learnt that efficiency and rebound height is not just about mass, but material also. So in conclusion yes my theory was disproven, but it is all about learning.

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