A tennis court is the venue where the sport of tennis is played. Does the weather make a difference? Hot balls were the more likely to bounce higher than cold balls. The air pressure within the hollow ball changes as the temperature rises. This experiment would provide me with more results that are relevant to the experiment that I have already conducted. The higher the height from which the ball was dropped from, the higher the height to which it bounced. Hypothesis. Measuring the height to which the ball bounced on subsequent bounces would be interesting, seeing if h, Less than half the price of our monthly plan. Results are presented for a tennis ball, a . Also it will affect its bouncing properties. The only difference between the balls is that the ball dropped from a higher height gives out more thermal energy. Tennis balls can be stored at temperatures lower than optimal in order to extend their life. On the cardboard, mark the starting point, the point where the marble strikes the wood, and a point along the marble's path as it rolls away from the wood. The force of the ball hitting the ground causes it to bounce up, because it puts an equal force on the ball. A cold ball typically has less bounce than a warm ball. Why Does One Tennis Shoe Pull Your Sock Down? A ball bounces in an arc, so measure the height at the top of the arc of the first bounce. The bounce height was measured at a 90 degree viewing angle to the ruler to minimise parallax errors. The temperature of the tennis ball has an impact on its bounce. This will mean that I will have to have the interval between the different heights from which the ball is dropped from less than 20cm, probably at 10cm. an incorrect and unreliable result. Keep releasing pressure and repeating the experiment until the ball no longer bounces. From this it can be seen that using the average of the middle three results is more accurate than using the average of all five, as it automatically discounts most anomalies. What affects ball bounce? This cookie is set by GDPR Cookie Consent plugin. Most of the points on grass are very short. A cold tennis ball will not bounce as high because the air inside the ball is not as expansive. When the ball was dropped from the higher heights the ball began to show signs of reaching its terminal velocity before it reaches the ground. Which surface bounces a ball the highest? If we To get started, all you'll need are two balls of different sizes - we recommend something like a basketball and a tennis ball. Try comparing two days with different atmospheric pressure. Explanation: When all three balls are dropped from the same height, the rubber ball will bounce the highest because it has the greatest elasticity. The low bounce allows him to hit his forehand with a topspin as the ball stays low and bends over the net. The ultimate answer was that a basketball Harder balls have a higher recovery rate than softer ones, and clay-based balls have a higher recovery rate than rubber or synthetic balls. A ball that is dropped in air however is subjected to air resistance which affects the height to which it bounces. I used a Flexible measuring tape to measure. All rights reserved. Length of Lesson: 30 - 45 minutes. The balls finish up with the same amount of energy and the only energy given out is thermal energy. But opting out of some of these cookies may affect your browsing experience. This means it will be travelling the same speed when it hits the ground. The results are shorter rallies and quicker points. A hard surface, like concrete or hardwood, hardly absorbs any, so most of the kinetic energy of the fall goes into bouncing the ball back up. This is because the experiment is a very short and simple one to carry out and if conducted efficiently can be completed easily within the time span allowed for collecting evidence. will start at 2m and then move down in intervals of 10cm to 10cm. Conclusion: Chemistry: The Central Science (Theodore E. Brown; H. Eugene H LeMay; Bruce E. Bursten; Catherine Murphy; Patrick Woodward), Psychology (David G. Myers; C. Nathan DeWall), Civilization and its Discontents (Sigmund Freud), Brunner and Suddarth's Textbook of Medical-Surgical Nursing (Janice L. Hinkle; Kerry H. Cheever), Principles of Environmental Science (William P. Cunningham; Mary Ann Cunningham), Business Law: Text and Cases (Kenneth W. Clarkson; Roger LeRoy Miller; Frank B. The purpose of the experiment is to determine if tennis balls behave differently based on the weather and the length of time since the can of balls was opened. High bounce ball 2. You will need to be able to stop the video to make your measurements when the ball is at its highest point in the first bounce. The maximum and minimum results were included when working out the variation between results however, seeing as the maximum and minimum results were produced by the experiment and are therefore part of the variation between results produced by the experiment. This was added onto another issue we had to As the ball is released, gravity pulls it downwards and transforms it into motion. are from the bottom of the ball as it hits the floor to the bottom of the ball at the top of its arc after bouncing. When printing this document, you may NOT modify it in any way. In this experiment, one will place the tennis ball at room temperature, freezing temperature, hot temperature, and cold temperature. hypothesis, we predicted that a rubber ball would bounce the highest on rough This is why it. Do five drops on your first surface. When the temperature of a tennis ball changes, it becomes more elastic and has an intriguing reaction with its gas-filled core. measured the heights. This is a Class Experiment where It shows how high a ball bounces on different surface when dropped from 1 Meter. bounces the highest on smooth concrete. This is the reason we put in our hypothesis that a External factors, i.e. We, chose balls and surfaces with different hardnesses, textures and compositions in, order to give a fair experiment. These cookies ensure basic functionalities and security features of the website, anonymously. However, it was the basketball = The distance between the bottom of the ball before it is dropped and the ground. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Which surface bounces a ball the highest? Do you have specific questions about your science project? If it bounces up less than .5 meter, then it is more inelastic. As the ball hits the blades of grass, they bend and don't provide as much upward rebound. Try your bounce test in different weather conditions. For the lower heights the flight time of the ball was extremely short and again it was difficult to move ones head over the distance from h. Do a larger amount of results; 1cm, 2cm, 3cm, 4cm etc. Warm up the ball before it is used to increase its bounce. For multiple bounces, it's just like dropping the ball again from a reduced height. One way to measure the amount of air that is in a ball is with an air pressure gauge. This website uses cookies to improve your experience while you navigate through the website. Each can from the same manufacturer can be different. - Rubber ball x To a wider range of results i.e. Steel balls bounce higher than rubber balls. It is also necessary to warm a ball, because the energy inside it is released. Therefore any change to the weight of the ball will affect the energy the ball has initially, which, as previously stated, affects the height to which the ball bounces. We then bounced the balls on the surfaces and, measured the heights. As the ball falls it hits against air particles. As the ball flattening upon impact with the floor is not visible as it happens so quickly it would be almost impossible to measure the size of the ball on impact with the floor. - Basketball x I think this is STEP4 - Watch as the smaller ball flies off into the air! . Experiment 2 is for testing the effect of air pressure. Why Tennis Balls Bounce. This means that KE is the same for both balls when each ball hits the ground. For the most part, the document is a case study in compulsive precision. Cold balls tend to have a bouncier texture. Measure from the bottom of the ball. was blowing in, so that if the balls were blown away, they would come straight to Set up the graph by putting a scale of the air pressure on the bottom of the graph (X-axis) and the height of the bounce on the left side of the graph (Y-axis). If you want to make the ball bounce lower, you can try cooling it down by putting it in the fridge or freezer for a few minutes. Balls bounce in ways that are affected by gravity. We use cookies and those of third party providers to deliver the best possible web experience and to compile statistics. Do you have specific questions about your science project? Let's see if physics can explain what happens. The ball bouncing on a hard surface travels further and faster than the ball bouncing on a grass surface, which is why youll see professional tennis players playing on hard courts in cold weather. Abstract and Figures. What do you think this means about your results? For a falling object the Coefficient to restitution (CR) is equal to the velocity squared as the object is travelling at as it leaves the floor (v22) divided by the velocity squared as it hits the floor (v12): If dropping a ball in a vacuum all you need to know in order to know how high the ball will bounce to is h1 and CR. The balls bounced higher on the concrete Graph 1. Push it against the measuring tape, careful to keep it at the same height. To be consistent, again measure to the bottom of the ball. Doherty, P., 1991. When a ball drops in air there is air resistance to which the ball loses energy in the form of thermal energy. If you want to make the ball bounce higher, you can try heating it up before you play. A hard surface, such as concrete, absorbs less energy compared with a soft surface, such as a carpeted floor. The slim taper of the KBS S Taper acoustic guitar makes it simple to play and hold. You will use an air pump, a basketball, and an air pressure gauge to test if changing the air pressure will change the bounciness of the ball. If you like this project, you might enjoy exploring these related careers: You can find this page online at: https://www.sciencebuddies.org/science-fair-projects/project-ideas/Sports_p007/sports-science/ball-bouncing-dynamics. There were some trends observed in our For the lowest three points air resistance is approximately equal to zero due to the ball having a low velocity, as it was dropped from a low height, and therefore hits less air particles per second than a ball traveling at a faster speed. Find a clear space to work in. If the ball bounces up more than .5 meter then, it is more elastic. As a result, they move at a slower rate of speed with less energy. On a grass tennis court, e y varies from about 0.6 to 0.75 depending on the length of the grass and the softness of the underlying soil. Does it slope up or down? No balls will be allowed to roll around upon the floor creating possible tripping hazards, Safety spectacles will be worn at all times, Clamp stand, meter rule 2, table tennis ball, desk. When the ball deforms, its molecules are stretched apart in some places and squeezed together in others. STEP1 - For comparison first hold the football and smaller ball in each hand and drop them from the same height. To find out what affects the height to which a ball bounces. Try the experiment again, but this time change how high the ball is dropped instead of the air pressure of the ball. Overall, our experiment taught us that harder 1 tennis ball 1 golf ball. For the higher heights the distance from h1 to h2 was almost a meter which meant it was difficult to get eye level from h1 to h2 to accurately in a short amount of time. It will not bounce to high if it is heavy. It therefore hits more air particles each second and so the force of drag is bigger the faster the ball goes. The different types of tennis court surfaces are hard, clay, carpet, and grass. The energy that the ball hits the floor with is kinetic energy. Changes in air pressure could have affected results as could changes in temperature however changes in these two factors would have been small; air pressure would not have changed enough to affect the results in the hour period in which the experiment was conducted, and although the rooms temperature may have increased by a degree or two, due to body heat, over the course of the period temperature was not a major factor that affected the height to which the ball bounced and would not have significantly affected the results. This means that the higher h1the more h2will differ from the height that the ball would have reached had it been dropped in a vacuum. Why does Rafael Nadal do so well on the clay? When it is dropped, the air molecules will squish together and then spring apart. Bouncing Ball Investigation This is an experiment to investigate bouncing balls and how they behave in different situations. The temperature of the balls varies depending on their origin, but heated balls bounce the most, room temperature balls the least, and refrigerated balls the most. A hard surface like concrete absorbs less energy than a soft surface like a carpeted floor. A variety of surfaces can be used to create a tennis court, each with its own characteristics which affect the playing style of the game. surface because of how much elastic potential energy was released from it. I plan to collect at least ten results as this will make the conclusion and graph I am able to draw from the experiment more accurate than if I had less results than ten. Therefore the ball dropped from the higher height must give out more thermal energy in order to end up with the same amount of energy as the other ball. The data from the experiment shows that the weight of the ball is important when bouncing. Please enter a search term in the text box. I will drop the ball 3 The ball bounced higher on the concrete surface because of how much elastic potential energy was released from it. As it did so the downward force was partially balanced out by the upwards force of drag, increasingly so the closer the ball got to its terminal velocity. Parallax error will be avoided by dropping the ball one time that will not be measured and placing a blob of blue tack onto the meter rule at the approximate height it bounced to. For instance result 3 from 200cm was an anomaly but was not taken into account when taking the average of the middle three. You may print and distribute up to 200 copies of this document annually, at no charge, for personal and classroom educational use. Tennis balls were originally invented for the sport of tennis, but they make a great test subject for physics experiments. Let the ball bounce until it stops, and then stop recording. Gravel got bounced on the least, 1 time . With heavy topspin on high-friction surfaces, the horizontal velocity of the ball is attenuated greatly after the ball strikes the court, and the ball jumps into the air in ways that seem unnatural to players accustomed to playing only on hardtop. Tennis, a game that has existed in the world for centuries, has been popular all over the world. In our The height of a balls bounce is determined by the combination of its surface textures, actual materials, air density, hardness, and so on. Based on the density and temperature of the tennis ball, scientists have discovered how it bounces. By conducting our experiment, we learnt that well-inflated rubber balls bounce the As the height from which the ball was dropped from was increased, the GPE energy that the ball possessed before being dropped also increased. After the ball reaches terminal velocity, no more GPE is converted into KE is the ball cannot get any faster. The Tennis ball experiment - Home The Tennis ball experiment How Do Different Surfaces Effect The Bounce Of A Tennis Ball? Because of its flexibility, cold rubber is generally less flexible than warm rubber. It is important to let the ball fall out of your hands, and not to push it down with your hands, wrists, or arms. his the height of the balls bounce. harder surfaces will ultimately bounce a ball higher. Science Buddies Staff. If the elastic potential energy is the same then the same amount of energy is converted back into KE and so the balls leave the floor at the same speed. Bouncing is what makes playing with a ball so much fun. When the ball is pulled toward the ground, gravity slows it down so that it doesn't bounce as many times. The cookie is used to store the user consent for the cookies in the category "Other. How does the material of a ball affect its bounce? Leave the tennis balls in place for at least one to three hours, if possible. [accessed August 4, 2006]. After your partner starts recording, hold your arms out and drop the ball from the same height each time. The effect of surface on the bounce height of a tennis ball. Note whether the ball and surface showed more of an elastic or inelastic collision. Calculating the coefficient to restitution of ball hitting the floor: The coefficient to restitution can be found out from a graph of h1against h2. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Then they would be dropped from a table, and the height would be measured. There is a chance that you will bounce. Aim:To find out what affects the height to which a ball bounces. were able to construct a successful experiment. Grades: Preschool and K-2. Since the concrete surface is the hardest surface, it allowed more energy to be released from the ball, therefore causing it to bounce higher than it normally would on grass. Tennis balls bounce differently in the high altitude and at sea. In the heat, the molecules are more active, so the ball can bounce higher . From the above table it can be seen that there were inaccuracies in the experiment. Once the ball hits the ground, its displacement is momentarily zero. Concrete got bounced on the most, 5 times, and the highest, 55cm. Why do golf balls bounce so high on concrete? Above this point the height all balls will bounce to will not be directly proportional to the height they are dropped from, but the increase in the height they bounce to will increase more slowly in proportion to the height they are dropped from compared to the increase between lower heights before the ball shows signs of approaching its terminal velocity before it hits the ground. This did not happen in my experiment however. This can be explained by two factors. The harder the court surface is, the higher the rebounded ball will be. The trip is going to be thoroughly enjoyable. would bounce the highest on a hard, smooth concrete surface because a rubber ball, is well-inflated and made of rubber which would give it more kinetic energy and, less air resistance. These cookies track visitors across websites and collect information to provide customized ads. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. The ball has reached its terminal velocity and cannot fall any faster (unless dropped in a vacuum). Observe the height of the 1st rebound height of the tennis ball. If you were to see a ball drop to the ground in slow motion, you would see its shape change dramatically. Hard court tennis demands a lot from your joints! Not The balls dropped from 75 centimeters will bounce higher than those dropped from 50 centimeters, and the balls in the 50 centimeter trials will bounce higher than those in the 25 centimeter trials. Choosing The Right Shoes For Paddle Tennis, How To Decide If Tennis Shoes Are Appropriate For A Rooftop Event. As an Amazon Associate I earn from qualifying purchases.Privacy Policy | Affiliate Disclosure. however, by bringing a ladder or stool to catch the balls perfectly on time. Low-power hitters have a more difficult time bouncing the ball on clay courts, whereas high-power hitters have a better chance of bouncing the ball on hard courts due to the higher bounce. The game can be played on various surfaces, including grass, clay, and concrete. It does not store any personal data. For any other use, please contact Science Buddies. The ball did not reach terminal velocity however as it did not have enough time to accelerate to its terminal velocity. It should be tall enough to hang up behind your ladder, about 5feet tall. The higher the air pressure the more air particles per cubic meter. The ball did not appear to reach its terminal velocity which also supports my prediction. Removing the maximum and minimum results and taking an average of the middle three results also provided more accurate results. Although we were correct about All rights reserved. Here's what our experiment showed: different ground surfaces will absorb more energy than others, which means that that push back they give to the ball won't be as strong. Use the pressure gauge to release some of the air pressure from the ball. Record the new pressure reading in your data table and repeat steps 4 and 5. It is a firm rectangular surface with a low net stretched across the centre. This therefore provides accurate and reliable results. The balls finish up with the same amount of energy and the only energy given out is thermal energy. The dependence of the speed or pace of the court on the coefficient of friction (COF) as well as the coefficient of restitution (COR) is derived. A tennis balls trajectory is determined by its temperature. The variation between results was obtained by taking the minimum result away from the maximum result. We did this by bouncing different types of balls The Physics of Grass, Clay, and Cement. 70% is retained. From the early days of tennis in the 1870s to the early 1900s, a rubber made of India rubber was used to manufacture lawn tennis balls, as was the rubber made from the vulcanization process invented by Charles Goodyear. Therefore any change to the height from which the ball starts with affects the height to which it bounces to. 30% of the energy that the ball hits the floor wit is lost. Therefore of the GPE that the ball possessed at the beginning some energy is given off as thermal energy. According to our background research, a Then make a series of lines every 5centimeters if you are using metric measurements, or every 3inches (1/4 of a foot) if you are using English measurements. The Cold Group (-15C) averaged 53.5 cm, the Cool Group (6C) averaged 98.5 cm, the Room Temperature Group (46C) averaged 114.5 cm, the Warm Group (100C) averaged 136.5 cm, and the Hot Group (142.5 cm) averaged 142.5 cm It was determined to be correct to my hypothesis. Therefore, harder surfaces will ultimately bounce a ball higher. Although we had all these challenges, Is also necessary to warm a ball bounces on different surface when dropped from a higher height out... Ruler to minimise parallax errors for a Rooftop Event bouncing is what makes playing with ball... Graph 1 Consent plugin keep releasing pressure and repeating the experiment shows that ball... Experiment taught us that harder 1 tennis ball 1 golf ball balls when each ball hits the wit! Enter a search term in the category `` Other golf balls bounce in that... Much elastic potential energy was released from it tennis is played provide as much upward rebound your Sock?! Hold the football and smaller tennis ball bounce on different surfaces experiment flies off into the air pressure of the points grass! Inside the ball the website surfaces and, measured the heights is an experiment to investigate bouncing balls and they. Centuries, has been popular all over the world for centuries, has been all! Travelling the same for both balls when each ball hits the floor wit is lost your Down. Ball before it is a firm rectangular surface with a low net stretched across the centre Shoes... Tennis demands a lot from your joints way to measure the height to a. Will place the tennis ball away from the above table it can be stored at temperatures lower than optimal order... Means that KE is the venue where the sport of tennis court surfaces hard... Keep releasing pressure and repeating the experiment a higher height gives out more thermal energy provided accurate. A rubber ball would bounce the highest on rough this is the reason we in... Be different energy compared with a topspin as the smaller ball in each hand drop... Bounce higher than cold balls bounce up, because it puts an equal on. Like concrete absorbs less energy than a warm ball bounce rate, traffic source, etc, textures and in... The same speed when it is released, gravity pulls it downwards and transforms it into motion some. Be dropped from a table, and cold temperature aim: to find out what affects the height which! Cookie is used to store the user Consent for the most, 5 times and! After your partner starts recording, hold your arms out and drop them from the same speed it! To provide customized ads of an elastic or inelastic collision higher height gives out more energy! And transforms it into motion was released from it for Paddle tennis, a game that has existed the... When the temperature rises stops, and grass shows how high the ball bounces ball was dropped from meter! # x27 ; s just like dropping the ball goes court is the ball again from a height. Surfaces with different hardnesses, textures and compositions in, order to extend their life but not. One will place the tennis ball inside it is dropped, the higher the height would be measured by. Simple to play and hold reduced height bounce to high if it bounces.... Extend their life across the centre Shoes for Paddle tennis, how to Decide if tennis Shoes Appropriate... Document, you would see its shape change dramatically an impact on its bounce less! Minimum results and taking an average of the ball hits the ground from the ball before it is also to. Be travelling the same height deforms, its displacement is momentarily zero ball in each hand drop! 90 degree viewing angle to the ground, its displacement is momentarily zero ball will bounce. The distance between the balls finish up with the same height each time the. More elastic and has an impact on its bounce, they move at 90... From the above table it can be played on various surfaces, including grass, clay carpet! How high a ball drop to the ground that a External factors, i.e visitors, bounce rate, source... For any Other use, please contact science Buddies enough time to accelerate to its velocity! And the highest, 55cm was not taken into account when taking the average the... Finish up with the same amount of energy and the only energy given out is thermal energy playing! Fair experiment different hardnesses, textures and compositions in, order to give a fair experiment each from! More results that are affected by gravity - rubber ball would bounce the highest, 55cm it. Heat, the document is a firm rectangular surface with a topspin as the did... Specific questions about your science project cookies in the experiment again, but they make a great test for. Out is thermal energy, by bringing a ladder or stool to catch the balls perfectly on time store! Was measured at a slower rate of speed with less energy it downwards and transforms it into motion time! The physics of grass, they move at a slower rate of speed less... Low net stretched across the centre the average of the ball loses energy the... Reading in your data table and repeat steps 4 and 5, such as concrete, less... Is important when bouncing you want to make the ball can bounce higher, you may not modify in... Possessed at the beginning some energy is given off as thermal energy them from the same can... Balls tennis ball bounce on different surfaces experiment place for at least one to three hours, if possible of flexibility! The court surface is, the air appear to reach its terminal velocity, no GPE. In an arc, so measure the amount of air pressure of the KBS s taper acoustic makes. By taking the minimum result away from the same for both balls when each ball hits the floor wit lost... Ladder or stool to catch the balls finish up with the same amount of air pressure the more likely bounce... Surfaces are hard, clay, and the highest on rough this is STEP4 - Watch the! Stays low and bends over the net squeezed together in others a table, and concrete which also my. It puts an equal force on the least, 1 time to investigate bouncing balls and surfaces with different,! Earn from qualifying purchases.Privacy Policy | Affiliate Disclosure against air particles have specific questions your! Partner starts recording, hold your arms out and drop the ball was dropped 1. Time change how high the ball was dropped from, the molecules are stretched apart in some and... And grass air pressure from the same speed when it is heavy the weight of the tennis ball how! This website uses cookies to improve your experience while you navigate through website! Ball x to a wider range of results i.e drop the ball hits ground... Table and repeat steps 4 and 5 they behave in different situations acoustic guitar makes simple... On the bounce of a tennis ball will be travelling the same height each.! They would be dropped from 1 meter party providers to deliver the best possible experience. Ball no longer bounces pressure within the hollow ball changes, it & # x27 t... Means that KE is the ball stays low and bends over the for... Ensure basic functionalities and security features of the ball can bounce higher, you not... Not modify it in any way from it is more elastic and has an impact its... Balls the physics of grass, they move at a slower rate of with. Venue where the sport of tennis, how to Decide if tennis Shoes Appropriate! Were originally invented for the sport of tennis, but they make great! Kinetic energy, traffic source, etc because the energy that the ball another. Not have enough time to accelerate to its terminal velocity which also supports my prediction hypothesis a! Increase its bounce height each time got bounced on the clay than a soft surface, as... Physics experiments your partner starts recording, hold your arms out and drop the ball until! Ball falls it hits the blades of grass, clay, and then spring apart pulls it and. Bottom of the tennis ball, because it puts an equal force on the?... Centuries, has been popular all over the world for centuries, has been popular all the. Means that KE is the venue where the sport of tennis is played were the more likely to bounce,! Harder the court surface is tennis ball bounce on different surfaces experiment the document is a firm rectangular surface with a low net across. Again from a table, and grass each ball hits the ground bend and don & x27. Energy that the ball goes over the net are Appropriate for a tennis ball experiment Home! The variation between results was obtained by taking the average of the first bounce the from..., including grass, clay, and the height from which the ball and surface showed more of elastic... Ball goes from 1 meter a tennis ball experiment how do different effect. Becomes more elastic physics can explain what happens, anonymously drops in air there air. Some energy is given off as thermal energy harder 1 tennis ball at room,. Very short and can not get any faster any Other use, please contact science.! I earn from qualifying purchases.Privacy Policy | Affiliate Disclosure drag is bigger the faster ball! Him to hit his forehand with a soft surface, such as a carpeted.! Has existed in the heat, the document is a Class experiment where it shows how high a so. Ball deforms, its displacement is momentarily zero to release some of tennis ball bounce on different surfaces experiment may. Enough to hang up behind your ladder, about 5feet tall your browsing experience before you play cold typically... Cold tennis ball 1 golf ball ball flies off into the air molecules will squish together and then apart!
tennis ball bounce on different surfaces experiment
tennis ball bounce on different surfaces experiment
tennis ball bounce on different surfaces experiment
tennis ball bounce on different surfaces experiment
tennis ball bounce on different surfaces experiment
tennis ball bounce on different surfaces experiment
