Method
Heat up the ball placing it in a beaker of boiling water. Measure temperature and drop ball at 1m. Measure temperature of water to determine the temperature of squash ball.
To get the ball at an accurate temperature the entire ball must be submerged. The ball will be taken out of the water as quickly as possible so I assume heat loss each time will be approximately 30 seconds.
Rubber isn’t a good heat conductor so the ball will be kept submerged for a period of 2 minutes.
The ball will be held at the 1 metre mark and then dropped. The height bounced will be recorded by the naked eye. Results will be recorded for each bounce. I will take 5 temperature readings and do each test 3 times and then average them.
Range
Temperature to + or – 1 degree.
3 readings at 10-degree intervals.
Ruler accurate to 1 mm
Apparatus
Squash ball
Beaker
Bunsen Burner
Gauze
Tripod
Thermometer
Water
1 metre ruler accurate to 1mm
Stopwatch
Tongs.
Diagram
Safety
Goggles because of Bunsen burner
Drop Vertically
Away from bounce zone
Use tongs to handle squash ball because of high temperatures.
Preliminary Readings
Observation
As the temperature increases the bounce height increases. I have chosen to do my readings at 10 intervals.
Procedure
I heated up the ball by placing it in a beaker of boiling water. I measured the temperature each time. I measured temperature of water to determine the temperature of squash ball.
To get the ball at an accurate temperature I submerged the entire ball. The ball was taken out of the water as quickly as possible. I assumed heat loss each time was approximately 30 seconds.
Rubber isn’t a good heat conductor so the ball was kept submerged for a period of 2 minutes.
The ball was held at the 2-metre mark and then dropped. This was because from the preliminary readings I found that I couldn’t get adequate readings by dropping the ball from 1 metre. The height bounced was recorded by the naked eye. Although the ruler was accurate to 1mm I wasn’t confident enough to read it to 1mm so I read it to 1 cm.
Results were recorded for each bounce. I took 8 temperature readings so that I could get a better average and a better graph. I did each test 3 times and then averaged them.
Results
Analysis
The graph climbs up when the higher the temperature but it doesn’t bounce as much, at higher temperatures. Below 0 degrees it doesn’t bounce that much.
The graph shows that the higher the temperature the higher it bounces which proves Newton's 2nd Law that the force is proportional to the rate of change of momentum. As the change of momentum inside the squash ball is caused by the heat.
Conclusion
I have found from my results that as the temperature of the ball gets hotter the height of the bounce gets higher. This proves Newton’s second law of motion, which states that as the ball gets hotter the atoms get more energy and vibrate more.
When the ball hits the surface then the atoms are pushed together and because they are vibrating more they push each other further away causing the ball to bounce higher.
In this experiment the kinetic theory only lasted up to a certain temperature as temperature started to reach temperatures above 60 degrees the material started to melt.
At 0 degrees Celsius the ball will still bounce as the atoms are still vibrating. The graph proves that the theory works for this experiment, as it is a slight curve to start with.
However as the ball gets nearer the critical temperature the extra height it bounces becomes less and less. This is shown as the graph shows it is about to levels off.
The sketch graph I drew in my prediction matched the real graph showing that the scientific understanding I used to explain my prediction was correct.
Evaluation
Looking at my results I can say that they were quite reliable and accurate. I had two anomalous results after an average of 8 measurements.
I think that I did the experiment quite well although I found it hard to spot where the ball bounced up to. I have taken this into account as human error in accurately reading the where the ball bounced up to. It would have been better to record the bounce so I could zoom in and more accurately then I had done, however as I assume the human error was consistent and didn’t affect my results too badly.
To improve the experiment I would need to use specialist equipment like lasers so I could be sure where the ball bounced too as the surface I bounced it on, the lab floor, was in some places and I couldn’t accurately control where it bounced as I made sure no input force was used to drop the ball.
Another better way would have been if I used a squash ball made of a special material which could withstand higher temperatures so I could have been able to carry on my experiment to see when the graph actually levels off.
Also I would like to see what happened when the ball was at 0 degrees Celsius. However that would have meant using ice, which is a variable, I don’t think I could have accurately kept at a suitable level to measure.
I would like to do this to see whether the atoms still vibrated causing the ball to bounce. If it did I would like to carry on getting lower and lower to see whether there was a temperature where the atoms no longer vibrated (Which in theory is Absolute Zero which has never been reached).
