Problem: Does a tennis ball placed in a freezer for some time bounce higher than a normal tennis ball or is the height of its bounce smaller? Does the amount of time it is placed in a cool area or atmosphere affect the bounce?
Aim: To determine whether the temperature of a tennis ball affects how high it bounces?
Hypothesis: The normal tennis ball will bounce higher than the tennis ball that was placed in the freezer for some time as the air molecule inside are not affected but for the cool tennis ball its air is compressed affecting its bounce.
Equipment: - two tennis balls - a refrigerator - tape measurer - video camera - bluetack
Variables: Dependent Variable: The height of each ball after it is dropped from an equal height. Independent Variable: The temperature of one of the tennis balls is cooler compared to one that has not been changed in anyway Controlled Variable: - Same type of balls - Dropped from same height - Dropped in same environment - Dropped on same surface - Dropped with same pressure
Method: 1. Place one of the tennis balls in the freezer for 20 mins 2. Place the tape measurer against the edge of a wall using the bluetack 3. Place the video camera on a level that will be able to clearly record the experiment, whilst a person sits beside the tape measurer 4. Turn the video camera on to record everything that happens there onwards 5. Drop the tennis ball with the cooler temperature, with no added pressure of the hand, directly down but not in the way of the video camera 6. Drop the second tennis ball that was not changed, with no added pressure of the hand, directly down but not in the way of the video camera 7. Allow the person to observe the height of each bounce for each ball and record them down 8. Repeat experiment 2 more times to produce accurate results 9. Find the average for the results from the cooler tennis ball then the average of the normal tennis ball and record them down.
Conclusion: The bounce of the cooler tennis balls is smaller than that of the normal tennis ball which is evident through the results. This is due to the temperature change in the cooler ball. Additionally, the results prove the hypothesis correct stating that the normal tennis ball will bounce higher.