Wednesday, 19 March 2014

Squash Ball bounce height vs temperature

In this experiment you can investigate how the height at which a squash ball bounces is affected by the termpaerture of the ball.

Equipment

5 squash balls of the same type
Water bath with temperature control
Thermometer
Paper towels
Tongs
Digital video camera (high speed if possible)
Metre stick with clear markings
Clamps & stands

Method

Place the squash balls into the water bath set to 20 degrees Celcius and ensure they are completely submerged.
Leave the balls in the water for at least 5 minutes to ensure the temperature of the rubber has stabilised.
Set up the metre stick so one end is on the floor using the clamp and stand to support it.
Set up the video camera so there is room to drop the balls between it and the metre stick and so that it has a clear view of the metre stick scale.
Use the tongs to remove one rubber ball and quickly blot off any excess water using a paper towel.
Start the video camera and drop the ball from level with the top of the metre stick.
Repeat with each of the remaining 4 balls.
Stop the camera and note the recording time.
Increase the temperature of the water bath by 10 degrees and replace the balls in it, again for at least 5 minutes.
Repeat a new recording of the balls being dropped.
Continue increasing the water bath temperature and recording the balls being dropped at 10 degree intervals until you reach at least 60 degrees.
Finally review the tape to record the maximum height each ball reached on its first bounce.

Risk assessment

Slips and falls may occur if the floor gets wet, this should be prevented by drying the balls carefully and by mopping up any wet areas quickly.
At higher tempertures there is a risk of scalding from the water. Tongs should always be used to remove the balls from the water bath to prevent contact with the skin. Additionally the experiment should not be run at a water bath temperature higher than 60 degrees Celcius