Physics Design Practical
Research Question
How is the bounce-height of a ping pong ball affected by it’s temperature?
This research questions aims to find out how the temperature of a ping pong ball affects the vertical height bounce, after being dropped from 1 metre. I will be measuring the bounce height using a video camera to find the heightest point. I will use the top of the ball for ease of results.
Hypothesis: I believe that as the temperature of the ping pong ball increases, the bounce height will increase. This may be due to the expansion of air inside the ball causing higher pressure.
Variables:
Independant
Temperature of the ping pong ball. Measured using a contact-less, infrared thermometer.
Constants
Starting height of the ping-pong ball. This is kept constant at 1m at all times.
Same ping pong ball for each drop.
Same thermometer - contact-less thermometer may be differently calibrated, therefore systematic error reduced by using same device.
Dependant
The height after one bounce. This is measured using a video camera, set up as shown in fig. 1.
Method
Apparatus
• Ping pong ball
• Meter ruler, with each 5cm and 10cm marked with a coloured line.
• Retort stand
• Boss Clamp
• Video camera, operating at 30fps, with USB link to laptop
• Laptop with video editing software, enabling frame-by-frame playback
• Beakers, small & large
• Bunsen Burner
• Ice (crushed)
• Contact-less thermometer
Photo of set up:
Measuring variables
I will change the dependent variable using crushed ice cubes to lower the temperature, and a water bath to raise the temperature of the surface of the ping pong ball. Using the contactless thermometer will ensure I get an accurate reading. I will measure the height of the bounce using the video camera connected to the laptop. I will video the bounce, and then afterwards, using video editing