Does Temperature Affect the Bounce of Tennis Balls?

Purpose

The purpose of this project is to determine how tennis balls are affected by different temperature conditions.

After this experiment, one will know why tennis balls bounce differently after being left out in various weather conditions.

Hypothesis

If tennis balls are left in various temperatures, then the tennis balls left in the warmest environment will bounce the highest because when the temperature rises, the molecules in the tennis ball expand, and put more pressure on the outside of the ball.

Vocabulary

Pressure (p)Density (ρ)

Gas Constant (R)Temperature (T)

Perfect Gas Law (p=ρRT)Molecules

Background Information

A tennis ball bounces because of the gas inside. The gas moves around and pushes on the inside of a ball. When the ball hits the ground the bottom pushes in, then the ball springs back off the court, due to the gas exerting pressure on the inside.

Gasses have unorganized molecules that take the shape of their container

Gasses are compressible and expandable When temperature increases, molecules move

around more and expand, therefore putting more pressure on the outside of the ball

When temperature decreases, the molecules compress

Materials

36 new tennis balls Freezer Refrigerator Oven Room at room temperature Thermometer Large centimeter ruler Stepstool Video camera Hard Surface Hand Helper (to video-tape)

Set Up\Procedure

Balls heated in oven Balls left at room temperature

Balls cooled in refrigerator

Balls frozen in freezer Electronic thermometer

Set Up\Procedure (cont.)

My ruler Where I stood My dad video-taping the bounce

Collecting Data

Observe and video-tape each tennis ball bounce. After completed experiment, review tape and record results.

Data For All TrialsBalls Frozen in

Freezer (-5.5o C)

Balls Cooled in Refrigerator (2.1o C)

Balls Left in Room Temperature (20o C)

Balls Heated in Oven (93o C)

Bounce of Ball 1 69 cm 102 cm 122 cm 134 cm

Bounce of Ball 2 77 cm 101 cm 120 cm 136 cm

Bounce of Ball 3 66 cm 99 cm 119 cm 135 cm

Bounce of Ball 4 68 cm 99 cm 119 cm 138 cm

Bounce of Ball 5 64 cm 100 cm 119 cm 136 cm

Bounce of Ball 6 75 cm 97 cm 117 cm 139 cm

Bounce of Ball 7 69 cm 100 cm 118 cm 134 cm

Bounce of Ball 8 68 cm 101 cm 119 cm 137 cm

Bounce of Ball 9 77 cm 98 cm 119 cm 138 cm

Ball Bounce vs. Temperature

020406080

100120140160

Hei

ght o

f Bou

nce

(in c

m)

Balls Frozen inFreezer

Balls Cooled inRefrigerator

Balls Left in RoomTemperature

Balls Heated inOven

(-5.5o C)

(2.1o C)

(20o C)

(200o C)

Analysis

• The heated tennis balls bounced the highest because as the temperature rose, the molecules expanded and exerted more pressure when the ball bounced

• The experiment illustrated the perfect gas law, because it showed that when the temperature rose, so did the pressure

• The data for each set of tennis balls had a range of 15 centimeters or lower

Conclusion

The bounce of the tennis balls, from highest to lowest, was as follows:

• heated tennis balls• room temperature tennis balls (control)• cooled tennis balls• frozen tennis balls

Weaknesses\Improvements

Occasionally the bounce was not captured on the video camera, and it had to be redone. This may explain the larger range of data on the first data series (the frozen tennis balls).