To investigate how the temperature of a squash ball will affect the height of it bouncing off the floor when it is dropped from the height of 1m.

Fair Test

I will take into consideration the following measures to make sure I perform a fair test:

* The fact that the same ball is used each time. Using a different ball could mean that the height of bounce is different.

* That the ball does not get wet when placed in the water baths (it will reduce friction if it is wet). Putting it in a food bag and sealing it with a rubber band will achieve this.

Method

After asking my father, who used to play squash I found out that the colour of the dot on the ball is the mark of it's speed. Its size or weight will not matter as long as I use the same ball for each variable. This is due to the fact that I am only trying to find out how the temperature affects the height that it bounces.

* Place the ball in the freezer and then take out and drop from a height of 1m when it has reduced to the temperature of 5?.

* Then take the squash ball and place it on the table in the room for three minutes. It should, after three minutes, be at room temperature (20°C).

* I will then take the ball and drop it from 1m and record how high it bounces. I will repeat this three times, on after another.

* Then take the same ball and put it in a sandwich bag and seal it with a rubber band. This is to prevent damage from the water.

* Then I will place the ball in a water bath with a high temperature and wait for the ball to reach 5?c higher. Take out and drop again three times.

* Place the ball back into the plastic bag and back into the water bath until another rise of temperature of 5?c. I will then take the ball out of the plastic bag and again drop it from a height of 1m. I will repeat this three times, one after another.

* I will repeat this procedure until 60?c.

Results

Temperature (?c)

Test 1

Test 2

Test 3

Test 4

Test 5

Avg. Height

5?c

3

4

2

4

4

3.4 cm

20?c

21

20

21

21

22

21 cm

25?c

23

26

26.5

26

25.5

25.4 cm

30?c

28

27

29

28.5

27.5

28 cm

35?c

33

34

33

37

33

34 cm

40?c

39

41

40

43

41

40.8 cm

45?c

44

47

46

46

45

45.6 cm

50?c

51

51

52

51

49

50.8 cm

55?c

55

52

57

54

55

54.6 cm

60?c

59

60

62

58

61

60 cm

Analysis

According to my results above and the graph on the next page the height of bounce of a squash ball does increase when it is hotter. This is true to my prediction. This is because the hotter the molecules of air inside the more energy they have and more often they collide with the walls of the ball. When the ball hits a hard surface it gets compressed. The air molecules that are colliding with the walls of the ball now collide faster because of the decrease in volume. This is what makes the ball bounce up. If the air molecules are heated up and given more energy they will collide with the walls of the ball even more and faster as well which will just make the it bounce higher.

The results above also support my prediction because I stated that the hotter the ball gets the higher it will bounce. This could be because in a proper squash game the ball can also lose heat by coming in contact with the walls and strings.

Evaluation

The procedure and method in which the experiment was carried out was not very exact. First of all, I could have allowed more time for the ball to heat up as I had no way of making sure that the ball was at that certain temperature. I could have used a temperature gun to measure the exact temperature of the ball but that was not on the equipment list that I was able to pick from, and would also have been a waste of time as it was only a small experiment. Secondly, the readings could have been more accurate since it is quite difficult to see exactly how high the ball has bounced. I could have filmed the ball bouncing with a video camera and then played it in slow motion to see exactly how high it bounced, or taken a picture with a digital camera, but that would have been hard too. Thirdly, I could have repeated the experiment another three times to make sure it was a fairer test. These three things could have made my results more precise, reliable and would have improved it.

I still think that this evidence is sufficient enough to support the following conclusion: "The higher the temperature of the squash ball, the higher it will bounce."

This is because of the fact that my results showed that the higher the temperature of the squash ball the higher it bounced. For example when it was at 15°C it bounced an average 13.4 centimetres high and when it was at 60°C it bounced an average of 60 centimetres high. This is shown very clearly on graph.

If I were to do further work on how the temperature of a ball affects it's height then I would do the same experiment using tennis, table tennis and footballs and measure the height they bounce to at different temperatures. I would also do the same experiment with squash balls that have different speeds (for example one with a yellow dot or a blue dot). This would help me draw a clearer conclusion on the relationship between the temperature of a ball and the height that it bounces to.