My aim is to investigate how the temperature has an effect on the height of the bounce of a squash ball.

Heat on ball Investigation

Introduction Originally Gravitational potential energy (mph) is stored in a ball before its released. as the ball falls and the speed increases The potential energy of the moving ball is changed to kinetic energy (1/2mv2) then it looses all the potential energy as soon as is touches the floor. If there is no energy loss the energy (I.e. P.E and K.E) remains the same

The ball deforms and slows down as it touches the ground. Here the balls kinetic energy is causing the ball to deform. When the ball is deformed some of the energy is stored as potential energy and another name for this energy is elastic potential energy and this in some cases this energy is changed into heat and sound and some is converted to heat and sound.

As soon as the ball losses all its speed and reaches its highest deformation only then it looses its kinetic energy and it stops moving. And when some of its energy Is changed to heat and sound its kinetic energy decreases than its original gravitational potential energy. Here all the energy (elastic PE + heat + sound) remains the same.

And then when the ball turns back into its original shape the elastic potential energy is then changed to kinetic energy.

As soon as the ball leaves the ground it will begin to slow down as it rises and its kinetic energy is changed back to gravitational potential energy. Since some of its original energy has been changed to heat and sound it will finish up with less gravitational energy than it began with i.e. the rebound height is less than the starting height.

Additional Information

A solid expands when it’s heated. Inside, the molecules energize and bounce around the solid with enough energy have more energy and bounce around the solid. The hotter the solid becomes, the more they vibrate. This causes the solid to expand slightly when heated. Solids cannot be compressed because the molecules are already packed very close together. When the solid hits the ground the atoms push each other away forcing the ball to bounce higher. So this is another factor in consideration.

AI M

My aim is to investigate how the temperature has an effect on the height of the bounce of a squash ball.

Equipment:

· Meter rule - to make sure the drop height is 1m and to measure the bounce height

· Squash ball – to be able to conduct the experiment

· Beaker – to create the water bath

· Water – to create the water bath

· Tongs – to keep the ball below the water bath surface

· Thermometer – to ensure the water is at the right temperature

· Timer – to ensure the ball stays in the water bath for the right amount of time

· Kettle – to get the water bath to the higher temperatures

· Ice – to get the water bath to the lower temperatures

This is a basic diagram showing all the equipment and how it should be placed .

Method I will be using the temperature choice of 0°C to 70°C and I will be going up in 10°C. I will only be going up to 70°C because I know that after that temperature the rubber of the squash ball will become damaged. I went down to 0°C as it is the lowest temperature because after that point the water will reach freezing point. This temperature also shows a low bounce height and if the temperature goes any lower it would be very difficult to read the bounce height. I will be repeating each temperature 5 times to make sure correct results and to be able to get a fair average. Also I will be able to see any anomalies and not take them into account for my average. I will use a water bath in which I will put the squash ball. I will let the squash ball remain in the water bath for 3 minutes as I know from my initial work that it takes 3 minutes for the squash ball to reach thermal equilibrium. I will let go of the ball from a height of one meter as I have found from my initial work that this is a good height to provide me good results that gives a good variety of results and is suitable for all the other temperature’s bounce heights. Also, I will be taking the bounce height measurements from the bottom of the ball each time. I will record all the results in a table with an average column so that my results can be compared. Next I will put the results onto a graph to see if there are any patterns and how the results relate to the line of best fit.

This is a preview of the whole essay

To ensure the test is fair For each beaker I will be using the same amount of water to make the test fair, and I will make sure that the water in the water bath remains at the right temperature when the squash ball is in it to make sure that the squash ball will reach thermal equilibrium. I will also be making sure that the squash ball is left in the water bath for 3 minutes to make sure that the ball reaches thermal equilibrium. I will be using the same squash ball during the experiment so that there is nothing affecting the results except the temperature. I will be taking the measurement of the bounce height from the base of the ball each time so that the results are in proportion to each other and can be compared.

Prediction Before the ball is dropped I know that, energy is stored as GPE (gravitational potential energy). As the ball falls its speed increases and the GPE is converted to KE (kinetic energy), so half way through the fall half of the ball’s energy id GPE and half is KE. Just before the ball hits the floor all its energy is KE and none of it is GPE. Once the ball hits the floor, all the KE is converted to EPE (elastic potential energy) and some is lost as heat and sound energy which makes its energy less than its initial GPE. When the ball bounces back off the floor the EPE is converted back to KE, heat and sound. The ball will start to slow down as it rises and its KE is converted back to GPE but because some of its initial energy has been converted to heat and sound it will finish with less GPE than it started with.

So I think that the hotter the ball is, the higher the height of the bounce will be. I think this because I know from my that when the gas that is inside the ball is heated up, the volume of the gas will slowly expand and the molecules will start to move faster which will often make them hit the sides more harder. This causes the rubber to expand and contain more elastic energy. We could understand from this that the bounce height would be bigger because the more stretched the rubber is, the better it changes elastic potential energy into kinetic energy when the ball touches the floor and makes the ball bounce higher. Then, the hotter the ball is, the firmer it is and the quicker it will gets its shape back, so then it loses very few energy and then has more energy to use to bounce higher. On the other hand, I think that the lower the temperature of the ball, the lower the bounce height because I know from my background scientific knowledge that the molecules are moving slower and therefore won’t hit the rubber as often or as hard as at hotter temperatures. This would mean that the rubber wouldn’t be as good at storing elastic potential energy and converting it into kinetic energy when the ball hits the surface. The bounce height for all the temperatures will be much less than the original dropping height because energy is lost converting elastic potential energy into kinetic energy.

Risk assessment To make sure that the investigation is safe I ensure that there is no one around our working area so nobody could get hit by the ball. I will also make sure that when the ball falls on the floor at any point I will pick it up straight away so that nobody can fall over it. I will also make sure that if the beaker of water will be in the middle of the table so that it doesn’t get knocked off spilling the water and creating a safety hazard of a slippery floor and broken glass. I will also make sure that if there are any spillages, I will clear them up straight away to prevent anyone slipping.

Initial work I did some initial work to see what the best height is to drop the ball from is and how long I need the ball to heat up in the water bath for it to reach thermal equilibrium. To investigate the length of time the squash ball needs to be kept in the water bath to reach thermal equilibrium I put the ball in the water bath at 30°C. I left the ball in the water for 1, 2, 3, 4 and 5 minutes. After each length of time I dropped the ball from a metre height and recorded the bounce height. When the bounce height no longer changed, the first length of time that gave this height is the length of time the ball takes to reach thermal equilibrium. I repeated each length of time three times to make sure I got accurate results and was able to get an average which I could look at to see at which point thermal equilibrium was reached. My results are shown below:

I can see from this that thermal equilibrium was reached at 3 minutes because this was the point that 28cm at a bounce height was reached and because the height didn’t increase more than 28cm it means that thermal equilibrium was reached. This is why I am going to leave the ball in the water bath for 3 minutes for it to reach thermal equilibrium.

I Am going To investigate a appropriate height to let go of the squash ball , I will let go of the squash ball at 20°C, 40°C and 70°C from different heights to find a height that worked well for all the temperatures. The heights I let go of the ball from were: 0.50m, 0.75m, 1.00m, 1.25m and 1.50m. To ensure the temperatures of the ball were correct I kept the ball in the water bath for 3 minutes as I understand from my earlier original results that 3 minutes is the time it takes the ball to reach thermal equilibrium.

You can understand from this that 1 meter is a appropriate height that I can easily record all the heights down to the lowest temperature (0°C) and gives a first-class bounce height for 70°C so it satisfies both ends of the series of temperatures. This height gives a good choice of results so they can be shown easily in a graph and compared. I chose not to use the higher heights since even though they would also give a precise range of results and I would easily be able to understand the height of the ball at a 0°C temperature, it was unsuitable for my experiment since it meant that I would keep getting up onto the table to be able to reach the heights. This would cause a safety hazard and would not be suitable for the experiment when a meter will give just as even results and result range. Consequently from my initial work I will be using a drop height of 1 meter and leave the squash ball in the water bath for 3 minutes for it to reach thermal equilibrium. My results are shown in the table below:

Test Results

THIS TABLE SHOWS THE EFFECT OF HEAT ON A SQUASH BALL

From the results I have got I have been able to use the averages to plot points on a graph with a line of best fit so the information is obviously displayed and I can analyse the shape of the graph to see what it shows me.

From these results and the graph I have got I can understand that the 10°C average result was an anomaly so I chose to do it a second time to check the results. The second time these are the results I got:

This is the results which are much better and fitted in better with the line of best fit. So I have chose to use my new results for 10°C and discount my old results as they are not accurate and would not be of any use to the rest of the investigation.

Analysis: From these results I can understand that my prediction is right because when the temperature increases the height of the bounce also increases. I can understand this because as I know that when the gas inside the ball heats up, the volume of the gas expands and the molecules move more quickly and will often make them hit the sides harder and more often . This allows the rubber to get larger and then store more elastic energy. You can see from this that the bounce height is bigger as the more stretched the rubber is, the better it converts elastic potential energy into kinetic energy when the ball hits the floor and allows the ball to bounce higher. Also, the hotter the ball is, the stronger it is and the faster it will get its shape back, thus it loses little energy and then has additional energy to use to bounce higher. This proves that I am right because before the ball is dropped, energy is contained as GPE (gravitational potential energy). Since the ball is let go off its speed increases and the GPE is changed into KE (kinetic energy), so half way through the drop half of the ball’s energy is GPE and half of its KE. Instant before the ball touches the floor all its energy is KE (kinetic energy) and it’s not GPE (gravitational potential energy). As soon as the ball hits the floor, all the KE (kinetic energy) is changed into EPE (elastic potential energy) and some of it is lost because the heat and sound energy which makes its energy less than its original GPE (gravitational potential energy).as soon as the ball hits back off the floor the EPE (elastic potential energy) is turned back into KE (kinetic energy), heat and sound. Then the ball will soon begin to lose speed as it rises and it’s KE (kinetic energy) is changed back to GPE (gravitational potential energy)as some of its original energy has been converted to heat and sound it will stop with less GPE (gravitational potential energy) than it began with. This is the reason why the height of the bounce for all the temperatures is lower than the original height (1 meter).

Conclusion: You can understand from the evidence that my prediction was right as the higher the temperature of the squash ball, the higher the height of the bounce will be. As you can understand from the results the lowest temperature of 0°C gave an average bounce height of only 5m which would be 5% of its initial height.

On the other hand the highest temperature of 70°C gave an average bounce height of 58.4m which is 58.4% of its original height. This proves my prediction right as not only can you see from the results that the bounce height increases as the temperature increases, you can then see from these results that it must be due to the gas inside the ball heating up, causing the volume of the gas to expand and the molecules to move faster which will caused them to hit the sides more often and harder. This made the rubber expand and store more elastic energy. This meant that the bounce height was bigger because the more stretched the rubber became, the better it converted elastic potential energy into kinetic energy when the ball hit the floor and therefore caused the ball to bounce higher.

Evaluation

I think that my results were as accurate as I could have made them with relevant safety points carried out and I got good, reliable, accurate results. The only anomaly I got was at 10°C because the temperature kept dropping which made the average too low. I decided to do the test for 10°C again and my results were much better. The average result for 70°C was lower than the line of best fit because I think that once the ball starts to reach the higher temperatures the ball can’t keep on stretching and eventually it will reach its maximum stretch and therefore it won’t bounce any higher, it will level out. The 70°C point looks like it would be the start of a curve to the levelling out of the bounce height. Other than that my results are very accurate as they are all very close to my line of best fit suggesting that there aren’t any anomalies although some points are further away from my line of best fit than others. These aren’t anomalies though because not every point will be exactly on the line of best fit because it would have to be extremely well controlled and that isn’t possible in classrooms and unlikely to be possible in the most controlled laboratories. There will always be differences in the results no matter what so therefore I believe that my results were as accurate as possible.

My investigation could have been improved by:

· Not doing the test over two lessons so all of the equipment would be the same.

· Making sure that all the preliminary work was done before I did the actual experiment.

· Making sure the temperature was kept exactly the same and not letting it drop or increase by even 1°C.

· Doing more tests to make sure I get a very accurate average.

· Being quicker between taking the ball out of the water bath and dropping

· Not allowing the squash ball to some to the surface of the water bath at some points, keep it below the surface to make sure it definitely reaches thermal equilibrium.

I think my results were very reliable even though it was done over two lessons so some of the equipment wasn’t the same but it wouldn’t have made much difference as all the equipment was mostly the same and were all accurate. At the lower temperatures such as 0°C and 10°C it was hard to keep the temperatures down in a warm room and had increased by a degree or two which could have made a difference to the bounce height. This would explain why the 10°C point was higher than the line of best fit. Other than that we were very accurate with keeping the water bath at the right temperature and this was shown by the closeness of the points to the line of best fit.

To provide additional relevant evidence I could:

· Use temperatures that go up in 5°C instead of 10°C so I would have more information to show the relationship between the temperature of a squash ball and its bounce height.

· I could have a better way of seeing the bounce height by having a video camera set up about a metre away from the experiment to see where about the ball bounced and then have another camera close up to see a closer reading of the bounce height. When I play back the video, I would put it on slow motion and show it frame by frame recording the heights until the bounce heights start to fall. Then I would take the maximum recording I had for that temperature and that would be the bounce height. This would be very accurate because I would see a very close up measurement and because it would be in slow motion and frame by frame it clearly showed the bounce height and could clearly be read from the bottom of the ball. This is more accurate than using your eyes because the ball would bounce very quickly and you only have a split second to read the height and is very difficult.

MOHAMMED ABDUL KALIK SHAHEEN