The coefficient to restitution can be found out from a graph of, it follows the gradient of the graph change in h. . Newton's third law states that every force or action has an equal and opposite reaction. If the drag is less the ball will fall faster and is less likely to reach its terminal velocity. For instance result 3 from 200cm was an anomaly but was not taken into account when taking the average of the middle three. When you think you know what variables may be involved, think about ways to change one at a time. At this level, science becomes even more interesting and powerful.8. This was when the ball was falling in air. Use the same point on the ball (top) or (bottom) when judging both the height The following is a college level project, but some grade 9 to 12 students can also complete this with no problem. This causes the amplitude of the height to reduce over time and eventually come to a stop due to friction forces like air resistance, which are assumed to be zero in an ideal scenario. This proves that the higher h1the more h2will differ from the height that the ball would have reached had it been dropped in a vacuum. The positive and negative directions must be stated in each example. Identifying variables is necessary before you can make a hypothesis. 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. The same square of tiling will be used throughout the experiment so that inconsistencies between different floor tiles do not affect results. The acceleration due to gravity causes the ball to change direction and start moving downwards at stage 2. h2= The distance between the bottom of the ball at the top of its arc after bouncing and the ground. You are NOT going to perform this experiment. Also it shows inaccuracies in the experiment as it shows that heights were recorded that exceeded the height that the ball would have reached had it been dropped in a vacuum. Set individual study goals and earn points reaching them. Drag is a squared function of velocity and therefore as the ball drops drag increases a greater amount each second. This is why it. The material ball is made from will affect the ball as if it is smooth then the drag will be significantly less than if it is rough. Once the drag force equals the gravitational force all forces are equal and acceleration stops. However if two results are recorded that do not fit the trend of other results nor are close to results recorded for that height then the experiments accuracy would be brought into doubt. These polymers are tangled together and stretch upon impact. WebThis experiment,is an investigation into the maximum height of the bounce of a ping pong ball when it is first released.This is because of the unpredictability of the bounce not always reaching the same height.This we can assume their are many factors effecting the bounce of the ping pong ball.The following experiment will determine how different What factors affect the bounce of a dropped ball? Specially look for parts that discuss the gas pressure and physical properties of gases. 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. In this experiment the only variable that we modify is the release height and we keep all other variables unchanged. Use two people to measure the results; one person to drop the ball and one to measure the height to which it reaches after bouncing. When raw data gets processed mathematically, for example, it becomes results. Independent: - Type of surface the tennis ball is dropped on. Your challenge will be to find a way to determine your balls e, and the initial height of the ball when you first dropped it. As the ball falls it hits against air particles. This phenomenon is described by Newton's third law. A decrease in h1, assuming g and m stay constant, results in a decrease in m g h1which results in a decrease in GPE. We also noted after we finished the experiment that the student taking measurements sometimes stood above the height when taking the measurement and sometimes kneeled on the floor so they had a different angle on the meter stick, which may have affected the measurement. h1and h2are 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. Therefore the ball goes higher. The exact interval will be determined after the preliminary experiment, as will the number of heights that the ball will be dropped from. ", " My husband and son came with me for the tour. Everything you need for your studies in one place. If you are author or own the copyright of this book, please report to us by using this DMCA report form. You will need an assistant, so one person will drop the ball and the other person stands about 20 feet away and records how high it bounces. The bouncing ball example is an example used to study, A bouncing ball in an ideal scenario will continue this oscillatory motion. The average variation between results was 3cm. Removing the maximum and minimum results and taking an average of the middle three results also provided more accurate results. Stages of bouncing ball example, Panagi - StudySmarter Originals, Motion graphs of a bouncing ball, Panagi - StudySmarter Originals. For a dropped ball, the total mechanical energy is defined as the sum of its kinetic energy and its gravitational potential energy. The distance in centimeters from bounce 1 to bounce 2. In the bouncing ball example, external forces such as air resistance are assumed to be zero. However, the tennis ball we used may be a very old one, and to definitely prove that our hypothesis is wrong for most tennis balls we would need to repeat the experiment with many different tennis balls. The most valuable resources for teachers and students. Aim The aim of this experiment is to investigate the efficiency of a bouncing ball, and the factors which affect its efficiency. These are illustrated below. Constants: the same person takes all of the measurements, the same materials are used in every trial. Is a bouncing ball an example of simple harmonic motion? The ball did not reach terminal velocity however as it did not have enough time to accelerate to its terminal velocity. The first stage is where the ball bounces from the surface of the ground. Such variations in the bounce of a dropped ball rise questions that demand some research and investigation. The motion of the ball can be split into different stages depending on the direction of the velocity vector; these stages are listed below. Additionally we were able to practice reading a lab, taking data and making a graph. As elasticity and hardness decreases, part of the ball energy will be used to permanently dent or misplace or vibrate the surface, so ball will have less energy to bounce. Variables are By the time it reaches the floor, the ball is traveling quickly and it hits the floor hard. The variation between results was obtained by taking the minimum result away from the maximum result. With no net force, the acceleration = 0 and the ball falls at a constant velocity. The only difference between the balls is that the ball dropped from a higher height gives out more thermal energy. Using the slope and graph, we can estimate that the ball would bounce to 0.75 m if dropped from 1.5 m and bounce to 1 m if dropped from 2 m. It is difficult to say with certainty that a ball dropped from 100 m would bounce to 50 m. That is because the heights we dropped the tennis ball from were all under 1 m, and at a much greater distance there may be other factors that would contribute to the bounce height. This coefficient of restitution, e, is actually the ratio of the velocity of recession (upwards after the bounce) to the velocity of approach (downward before the bounce). of the users don't pass the Bouncing Ball Example quiz! Both potential and kinetic energy have units of Joules (J). will be 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. Variables that may affect the bounce of a dropped ball are: You may study the effect of any of these variables on the bounce of a dropped ball. The example of the bouncing ball is used to study projectile motion in mechanics. The experiment was conducted well however as the utmost efforts were brought into place to avoid parallax error and it was ensured as far as possible that factors that affected how high the ball bounced, excluding the height, were kept constant throughout the experiment. will start at 2m and then move down in intervals of 10cm to 10cm. Summarize what happened. A decrease in m, assuming g and h1stay constant, results in a decrease in m g h1which results A decrease in m, assuming g and h1stay constant, results in a decrease in m g h1which results in a decrease in GPE. h1 = The distance between the bottom of the ball before it is dropped and the ground. Prediction reasons for variable control: The height the ball is dropped from will affect the height the ball bounces to due to the energy chain the ball goes through as it is dropped and bounces up again. Changes in the area of linoleum floor tile that the ball collided with may have affected the height to which it bounced to thus producing variation between results. Averages are more reliable than using one result as they take into account variation between results. 3. The push which the ball receives from the floor at the moment of impact causes it to bounce up from the surface. If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. The format you use to write your bibliography may look like this: Are you ready for more advanced ball drop projects? A ball falls from a height of 6 metres. The controlled variables in this experiment are the surface the ball is rolling on, the material the ball is made of, the size of the ball, the measuring devices being used, the distance the ball travels, and the method being used to release the ball each time, for example the position of the hand. WebA) If a tennis ball is frozen, it won't bounce as high as one that is not frozen. Constants are the release height, the bouncing surface, the type and the size of the ball. Find sections related to potential energy, elasticity and springs. An average will then be taken. stay constant, results in an increase in m g h, stay constant, results in a decrease in m g h, The surface onto which the ball is dropped will affect the height to which the ball bounces because for any two objects that collide, the properties of both determine the percentage of the kinetic energy either possesses approaching the collision that is conserved subsequent to the collision taking place (Coefficient to restitution) discounting the effects of air resistance. WebBouncing Ball Experiment - Free download as Word Doc (.doc / .docx), PDF File (.pdf), Text File (.txt) or read online for free. A) Find the total distance of travel until the ball hits the ground for the 5th time. Stop procrastinating with our study reminders. Therefore the coefficient to restitution = 0.7. Often, mathematical equations can be made from graphs. This is Newtons Third Law of Motion- for every action there is an equal and opposite reaction. Find the total distance of travel until the ball hits the ground for the 8th time. This is correct unless the ball shows signs of reaching terminal velocity. Heres an example of an Excel spread sheet that analyzes whats going on: Heres a graph of energy vs. bounce from the spread sheet: Purpose: To determine how high a tennis ball will bounce when dropped from a specific height. The Controlled: - Same ball. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. Discuss specifically how you developed your e and initial height values. The equipment necessary to generate these conditions was not available and as a result the results obtained were not one hundred percent accurate. This did not happen in my experiment however. the initial height of your ball when you released it. 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. Controlled Variables: Bouncy ball used, surface bounced off of, technique in which ball was dropped (initial height was measured from base of ball). So if we double the air pressure, we will get double bounce height. As the ball hits the floor with less KE than it would have done if it had been dropped in a vacuum it follows that less energy is converted into elastic potential energy and back into KE again. Dependent Variable: The height of the bounce. This means that we can approximately calculate the amount of energy that the ball conserves as it hits the floor and therefore the height to which it will bounce for any given height in a vacuum. To do that use the scroll button to start, then use arrow keys to move your wave 0.1 second left or right. Taking an average of several results creates a measurement in the middle of the variation created by the experiment, which is the result that is closest to the height that would be recorded for the balls bounce if it were measured in an experiment that was totally accurate. Method:The apparatus will be set up as shown: H is the height of the ball before it is dropped. It is always good to have an explanation for choosing any hypothesis. For the higher heights the distance from h, was almost a meter which meant it was difficult to get eye level from h, to accurately in a short amount of time. H is the height of the ball before it is dropped. 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. Drop a ball from 1 foot off of the floor, slightly in front of a yardstick. WebControl variables include the size of pots, the type of soil and the position in a room. Draw a graph of bounce height Vs drop height. Experiment 2 is for testing the effect of air pressure. GPE=Mass (kg) Gravitational Field Strength (N/Kg) Height (m). GPE also changes as the ball falls. The coefficient of restitution is the ratio of the final to initial speed between two bodies after the collision. It was more reliable to use the middle three results as it automatically discounted any anomalies; assuming two similar anomalies were recorded for one height, if they were then they both would be discounted. Variables Independent variable = drop height Dependent variable = bounce height Controlled variables = ball, surface, measuring tool. This is also reflected in the velocity graph; the velocity is at its maximum at the minimum displacement and goes through zero at its maximum heights. 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. You will then take your bounces and their respective time intervals to a spread sheet. Yes, as the ball receives a force from the ground due to collision, which causes the ball to bounce off the ground. Being precise as the we drop the ball from a very big height the ball will bounce back at a very big height by Newton's The sum of the two, mechanical energy, stays the same ( is conserved.). Grammar mistakes. No, the bouncing ball example is not an example of simple harmonic motion. The energy that the ball hits the floor with is kinetic energy. The results of our experiment show that this probably is not the case. The decision for the size of interval and the amount of results collected will depend upon the time taken to conduct the experiment and any other factors that may become apparent during the preliminary experiment. Hold the ball at 6 feet height and release it on a hard concrete surface. Therefore the height that it reaches is less high. (Their ideas might include surface texture, colour, size, what its made of, squashiness, opacity, weight, air pockets, temperature, cost, shininess/dullness, hardness/softness, age, layers of materials.) 7. Based on your gathered information, make an educated guess about what types of things affect the system you are working with. 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. A series of experiments is made up of separate experimental runs. During each run you make a measurement of how much the variable affected the system under study. The ball pushes on the floor and the floor pushes back on the ball, causing it to rebound. If you change more than one at a time, you will not know what variable is causing your observation. D (60%) While a value of 1 indicates a perfectly elastic collision, a value of 0 indicates a perfectly inelastic collision. Air resistance exists but does not affect the velocity of the ball significantly. I called School Time and my husband and son came with me for the tour. This is a sample on how to write the results, conclusion and make charts. The dependent variable is how high the ball bounces. Control variables include the type of ball, the surface that it is dropped onto and the size of the ball. 3. Testing reaction times can be investigated by dropping a ruler and seeing how quickly someone can grab it. The independent variable is the person who is trying to catch the ruler. Its 100% free. An alternative method would be the measuring person holding a video camera level with the approximate height that the ball reaches after bouncing and videoing the ball reach the top of its arc. The experiment was conducted as the method (below) states. 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. This means for the ball to reach terminal velocity the drag force has to be bigger and for the drag force to be bigger the ball has to fall faster (so that more air particles hit the ball every second). Measure the height the ball reaches after the first bounce and record. Also the ball flattening upon impact doesnt have to be taken into account whereas if one was measuring from the top of the ball as it hits the floor to the top of the ball before dropping it or at the top of its arc after bouncing or the middle of the ball as it hits the ground to the middle of the ball before dropping it or the middle of the ball at the top of its bounce then the fact that the ball flattens momentarily on impact with the floor would have to be taken into account. Based on these trends, we can draw conclusions about the system under study. B) If this is an ideal scenario where energy is not lost and the ball continues to bounce infinitely, what is the distance of travel? Drag is a squared function of velocity and therefore as the ball drops drag increases a greater amount each second. Your bibliography must contain sources that are available to you (at your school or local library). B (81%) Synonyms. Kinetic energy means energy associated with motion. WebControlled Variables: Bouncy ball used, surface bounced off of, technique in which ball was dropped (initial height was measured from base of ball). The relative height of the bounce should be h/h = CoR2 = 0.72 = 0.49. What type of motion does a bouncing ball experience? This also proves the accuracy of the experiment. This project guide contains information that you need in order to start your project. It depends only on the elasticity of the ball itselfa super ball returns a large fraction while a beanbag returns a tiny fraction. What you have learned may allow you to answer other questions. Research questions pose a question about the Use a uniform surface to drop the ball onto. Controlled variables are air temperature, air flow, air pressure where you perform your tests. Is a bouncing ball an example of potential energy? A real-life bouncing ball example would experience an oscillatory motion which would gradually lose energy, causing the height of the bounce to reduce over time until eventually, the ball came to a stop. Either the coefficient to restitution that was worked out is incorrect, which would mean that the first three results are inaccurate or subsequent results were inaccurate. This is impossible. If you have any questions or need more support about this project, click on the Ask Question button on the top of this page to send me a message. Materials:-Carbon Paper-Goggles-Golf If the ball is elastic in nature, the ball will quickly return to its original form and spring up from the floor. Grades: Preschool and K-2 Length of Lesson: Approximately 45 minutes Related Video: The Hawk Factor episode Learning Goals: The surface onto which the ball is dropped will affect the height to which the ball bounces because for any two objects that collide, the properties of both determine the percentage of the kinetic energy either possesses approaching the collision that is conserved subsequent to the collision taking place (Coefficient to restitution) discounting the effects of air resistance. WebLearn how to identify types of variables in a simple experiment with bouncing balls. 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. If the common ratio of the sequence is between 0 and 1, then the term r would approach zero. The formula for kinetic energy is KE=1/2 mv 2 , where m is the mass in kg and v is the velocity in m/sec 2 . For each height repeat the test 3 to 5 times and record the most reliable result. Conveniently enough, this fraction of returned energy is nearly independent of how much energy the ball had to begin with. Either the coefficient to restitution that was worked out is incorrect, which would mean that the first three results are inaccurate or subsequent results were inaccurate. Try to find more information from physics or mechanics books. Kinetic energy is energy of motion. What is the force that causes a ball to bounce? It is also known as a constant variable or simply as a "control." This means that not all the GPE is converted into KE as it would have been if the ball had been dropped in a vacuum. CoR = coefficient of restitution = (speed after collision)/(speed before collision). \(v^2 = 2 \cdot g \cdot hv = \sqrt{2 \cdot 9.81 \frac{m}{s^2} \cdot 3 m} = 7.67 \frac{m}{s}\). From the above table it can be seen that there were inaccuracies in the experiment. Hence when a force is applied to a surface, it also applies a force equal in magnitude, but in the opposite direction. Have all your study materials in one place. ball bounced 6 inches. What is the control variable in the bouncing ball experiment? Hold the ball at 6 feet height and release it. http://wings.avkids.com/Curriculums/Tennis/index.html. 70% is retained. A bouncing ball is an example of oscillatory motion as the ball is oscillating about the equilibrium position. A control is a neutral reference point for comparison that allows you to see what changing a variable does by comparing it to not changing anything. 1. Potential energy is the energy of position, and it depends on the mass of the ball and its height above the surface. Dependable controls are sometimes very hard to develop. You may need to calculate the average of bounce height. The total energy of the system remains the same; the potential energy changes to kinetic energy, but no energy is lost. For an infinite number of turns, another geometric sequence formula can be used. We can go back to our table of velocities, square each one, then multiply by 1/ 2 * 0.044 kg to find the kinetic energy at each moment. List three. The purpose of this project is to find out what factors affect the bounce of a dropped ball. These stages can also be represented graphically using three plots including a displacement, velocity, and acceleration vs time graph. This therefore provides accurate and reliable results. Hypothesis. h1will start at 2m and then move down in intervals of 10cm to 10cm. use four meter sticks and go right the way up to four meters. If you get more than one value, calculate and record the average. 30% of the energy that the ball hits the floor wit is lost. Please note that many online stores for science supplies are managed by MiniScience. " Locate the peaks and record the time for each peak. As in both cases the main form of energy is GPE it follows that the higher the ball is dropped from, the higher the ball will bounce. Here, the motion of a real bouncing ball is shown. This means that the faster that the ball travels the larger the force of air resistance upon it. This applies to a ball falling in a vacuum. \(Area = \frac{1}{2} \cdot base \cdot length\), \(Area = 0.5 m \cdot 50 m \cdot 50 m = 1250 m^3\). Research questions therefore always refer to two variables, and the relationship between them. An investigation of the factors that influence the bounce height of a tennis ball when dropped onto the floor could consider the drop height and the type of surface the ball is dropped onto. The investigation could try to answer these research questions: Click Create Assignment to assign this modality to your LMS. When the ball collides with the floor, the ball becomes deformed. Our lab group was able to determine the relationship between drop height and bounce height. Air pressure will affect the balls fall slightly as the concentration of air particles per cubic meter varies with air pressure. The moving ball gains kinetic energy when it bounces, and loses potential energy as it falls. Since v2 = 2gh, the CoR = v/v = sqrt(h/h) where h is the height of the bounce and h is the height from which the ball is dropped. The purpose of our lab was fulfilled. Several meter sticks for measuring the height of the bouncing ball or drawing a larger meter stick. This means that KE is the same for both balls when each ball hits the ground. This experiment might have been improved if we had developed a method for more accurately measuring the tennis balls bounce height. So once you know how to calculate KE and GPE, it is simple to calculate their sum, E. KE of a dropped ball changes as it falls. They identify variables to be changed, measured and controlled. Data table 2 indicates that on average tennis ball bounced to a lower height than it was dropped from. This would allow the actual coefficient to restitution to be calculated. If you are new in doing science project, click on How to Start in the main page. This is because the ball starts with more GPE. It is used to determine what the variable changed. If the coefficient to restitution = 0.7, a ball dropping from h, in a vacuum would reach the height of 0.7 h, As velocity increases air resistance increases in proportion to the square of the velocity. CR can be found out by looking at a graph, the gradient, as a percentage of 1 gives the amount of energy conserved and therefore CRcan be found without knowing v22or v12. When you hold a ball above a surface, the ball has potential energy. We felt the magic immediately. The higher h1, the faster the velocity that the ball reaches. 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. 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. By the time the ball comes briefly to a stop, most of its missing energy has been stored in its dented surface. What are the variables in the ramp experiment? It is also good to calculate the coefficient of restitution of your ball using the formula CoR = v/v = sqrt(h/h). While these variables are not the it seems the ball is experiencing an oscillatory motion. The selection of balls for official games in most sports (esp. This slope tells us how bouncy the ball is. It was difficult to accurately measure the height of the bounce. These are parts of the experiment that you try to keep constant throughout an experiment so that they won't interfere with your test. It bounces off, changing the direction of motion and again reaching its maximum height. As the ball falls through the air, the Law of Conservation of Energy is in effect and states that energy is neither gained nor lost, only transferred from one form to another. WebAll experimental investigations involve variables. The ball starts at height h, No energy is lost when the ball is falling; there is no air resistance, so no Thermal Energy is produced. We felt the magic immediately.". Dependent: - Height at which the tennis ball bounces. Our dependent variable was. When dropped on a solid surface, not even a super ball bounces back as high as its initial height, but some balls do bounce a lot better than others.