Year 10 Science Project
Year 10 Assessment Task 1
Science Project
Year 10
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Year 10 Science Project
Aim:
To see whether the temperature of a tennis ball determines how high it will
bounce.
Hypothesis:
The higher temperature of the tennis ball will make it bounce higher than a
cold ball. Due to the fact that a tennis ball is filled with gas and gas will change
pressure with temperature, for a given mass and fixed volume.
Equipment:
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•
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•
•
•
•
•
•
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12 Tennis balls,
2m ladder,
8m tape measure,
Non-contact infra-red thermometer,,
Kitchen scales
concrete slab,
video camera and stand
A fridge.
A freezer
oven
Variables:
Independent:
• The temperature of the tennis ball.
Dependent:
• Bounce height of tennis ball.
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Year 10 Science Project
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Year 10 Science Project
Controlled:
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•
•
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Tennis balls used (all the same batch, from the same brand),
Landing surface (a concrete paver)
the height dropped and
The person dropping the tennis balls.
Method:
1. Set up concrete paver (bounce surface), ladder and drop height marker
along with the bounce scale (tape measure).
2. Place the tennis balls in the freezer overnight then take out one tube
(four balls) at a time
3. Measure and record the tennis balls surface temperature at 4 equally
spaced points.
4. Drop 12 tennis balls and record the height reached on the first bounce
using a digital video camera
5. Place the tennis balls in the fridge overnight then take out one tube
(four balls) at a time, to limit temperature variation.
6. Measure and record the tennis balls surface temperature at 4 equally
spaced points.
7. Then repeat the same drop test as before from the exact same height
and by the same person, recording the results in the same way.
8. Leave the tennis balls in the sun on a window sill overnight.
9. Then repeat the same drop test as before from the exact same height
and by the same person, recording the results in the same way.
10.Place the tennis balls in the oven at approximately 50*c for 1 hour then
take out them out and repeat the experiment one last time.
11.Gather all the bounce height recorded and plot them on a graph.
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Year 10 Science Project
Safety and Risk assessment:
Risk Identification
Risk Management Strategy
Fall from Ladder
Anchor the ladder firmly
Do not rush the experiment
No mucking about with tennis balls
Clear everyone from the area of test
Use only one brand of tennis balls
from the same batch
Everyone does the same jobs
(temperature measurement,
recording, ball drop)
Wall mounted Bracket to make drop
heights the same.
Balls all numbered with permanent
marker
Each test announced on camera like
the Mythbusters do
Record the drop tests with video
camera to get exact height.
Keep balls in canisters to stop them
getting wet or dirty
Weigh balls before each test
Impact from tennis ball
Inconsistent ball bounce
Inconsistent experimental procedures
Balls dropped from different heights
Mixing up different balls & results
Hard to measure bounce height
Change in ball weight
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Year 10 Science Project
Results:
Experiment Balls from Freezer
Date
21/02/2017
21:10
Ball #
Weight (g) Temp 1 °C Temp 2 °C Temp 3 °C Temp 4 °C AVG Temp °C Height (cm)
1
59
9.7
8.6
8.4
9.0
8.9
90
2
60
5.3
1.5
4.6
5.7
4.3
93
3
58
10.5
11.0
6.0
10.2
9.4
87
4
58
7.3
11.0
8.0
9.1
8.9
102
5
58
2.8
1.9
2.3
0.9
2.0
57
6
59
2.5
5.6
3.2
2.4
3.4
58
7
57
3.8
0.7
0.5
3.1
2.0
61
8
59
6.6
9.1
8.5
4.5
7.2
63
9
58
1.5
-2.0
-0.5
1.3
0.1
51
10
57
1.5
0.9
3.2
-0.3
1.3
56
11
60
4.1
3.3
1.6
4.3
3.3
60
12
59
4.0
3.5
5.8
3.7
4.3
63
Experiment Balls from Fridge
Date
25/02/2017
13:50
Ball #
Weight (g) Temp 1 °C Temp 2 °C Temp 3 °C Temp 4 °C AVG Temp °C Height (cm)
1
59
12.3
14.1
12.9
13.5
13.2
108
2
58
14.0
14.5
13.9
13.6
14.0
102
3
58
13.6
13.5
14.7
13.7
13.9
111
4
58
12.7
12.0
14.0
13.9
13.2
106
5
58
12.3
12.2
14.1
12.2
12.7
104
6
59
12.8
13.1
14.0
14.7
13.7
96
7
58
12.4
11.6
14.0
12.2
12.6
105
8
58
12.9
13.2
12.5
12.4
12.8
91
9
58
11.8
11.0
12.4
12.2
11.9
96
10
57
12.1
13.8
12.7
12.0
12.7
103
11
58
15.1
14.6
14.9
15.0
14.9
112
12
58
14.7
14.9
14.5
14.3
14.6
110
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Year 10 Science Project
Experiment Balls at room temperature
Date
27/02/2017 18:30
Ball #
Weight (g) Temp 1 °C Temp 2 °C Temp 3 °C Temp 4 °C AVG Temp °C Height (cm)
1
58
25.4
25.6
25.5
26.3
25.7
126
2
58
25.1
25.0
25.4
25.3
25.2
129
3
57
25.0
25.6
25.8
25.3
25.4
137
4
58
24.7
25.0
24.9
24.6
24.8
122
5
58
24.3
24.7
25.0
24.9
24.7
131
6
58
24.4
24.5
24.6
24.5
24.5
124
7
58
24.0
24.7
24.8
25.1
24.7
135
8
58
24.0
24.4
24.6
24.6
24.4
140
9
58
23.9
24.7
24.6
24.8
24.5
133
10
58
24.3
24.6
25.1
24.8
24.7
140
11
58
23.8
24.5
24.3
24.6
24.3
128
12
59
24.2
24.4
24.4
24.4
24.4
129
Experiment Balls from the oven
Date
27/02/2017
20:05
Ball #
Weight (g) Temp 1 °C Temp 2 °C Temp 3 °C Temp 4 °C AVG Temp °C Height (cm)
1
58
41.1
42.0
44.3
39.9
41.8
150
2
58
43.8
44.0
39.8
42.6
42.6
143
3
58
39.5
40.0
40.0
37.5
39.8
147
4
58
42.6
53.4
44.6
44.1
46.2
153
5
58
56.4
49.1
53.4
38.3
49.3
146
6
58
44.5
38.8
41.3
40.9
41.4
148
7
58
47.0
40.9
46.9
43.5
44.6
151
8
58
41.1
47.8
40.4
38.4
41.9
146
9
58
39.6
40.5
48.6
38.8
41.9
147
10
58
43.0
50.3
41.3
42.3
44.2
149
11
58
51.9
45.7
42.6
48.8
47.3
146
12
58
42.8
38.5
36.4
38.2
39.0
148
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Year 10 Science Project
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Year 10 Science Project
Discussion:
There we some difficulties the beginning of the experiment, with the capturing of the
bounce height, because the camera was not able to record in single frames. Also the
measuring scale was hard to see. The camera was changed to an IPad which worked. The
results recorded show a clear link between the surface temperature of the tennis ball and
the height it bounced to when dropped from a consistent height. In the initial tests at very
low temperatures of 2°C or less, the balls were bouncing at 60cm or lower. At the high
temperature end of 40°C to 45°C the balls were bouncing at 145-150cm. If there were more
in between temperatures it may be possible to graph more accurately and work out the
actual relationship between the temperature and bounce. Then it would be possible to
predict ball behaviour under different conditions. This would be useful for tennis players as
they would know, based on the tennis court temperature what the balls would do. Also if
people were crazy enough to play tennis outside in arctic conditions, they would know how
little bounce they would get.
The temperatures recorded for the fridge & freezer experiments show that the tennis ball
canisters seem to act as insulators. As the tennis balls were not at the same temperature as
the fridge (4°C) or the Freezer (-16°C) after 24 hours. The ITF (International Tennis
Federation) insists on balls being acclimatized in their lab for 24 hours prior to testing (ITF
Approval Tests). Also they insist on balls used for high altitude tournaments be acclimatized
for 60 days (appendix 1). The tennis balls were kept in the canisters to minimise the chance
of them getting dirty or wet and becoming heavier. The balls were also weighed before each
drop test to make sure they had not changed significantly
The infra-red thermometer used was reading the surface temperature of the fuzz on the
ball, but the ball bounce is more likely to be affected by the temperature of the rubber
casing & the gas inside the ball. Finding some way of measuring the temperature of the
rubber itself may give better results. Measuring at four different points gave very different
readings, handling the ball probably affected the low temperature readings. Ski gloves or
similar could be used to control this risk, but would make climbing the ladder hard.
Conclusion:
The aim of the experiment was to see whether the temperature of a tennis ball determines
how high it will bounce. The hypothesis was that bounce height it would vary directly with
temperature, which was proved. As, in the low temperature experiments the ball bounce
less than half (60cm) the height reach in the high temperature experiments (140cm).
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Year 10 Science Project
Bibliography:
International Tennis federation, APPENDIX I: THE BALL
(http://www.itftennis.com/technical/publications/rules/balls/appendix-i.aspx)
International Tennis federation, APPROVAL TESTS
http://www.itftennis.com/technical/balls/approval-tests.aspx
Bullet Fired vs. Bullet Dropped Mythbusters Episode 125 – "Knock Your Socks Off" Original
air date: October 7, 2009
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Year 10 Science Project
Experiment Layout
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Year 10 Science Project
Equipment
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Year 10 Science Project
Fridge in use
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Year 10 Science Project
Experiment in progress
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