controlled variables in bouncing ball experiment

If the coefficient to restitution = 0.7, a ball dropping from h1in a vacuum would reach the height of 0.7 h1 after bouncing. Why if you drop a ball from say 2 meters does it bounce higher than a ball dropped from 1 meter? This would provide evidence on how the height from which the ball is dropped from affects the height to which it bounces without air resistance. 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. It goes back to its initial vertical position after a period of time. Therefore the ball ends up with more GPE, , assuming g and m stay constant, results in an increase in m g h, , assuming g and m stay constant, results in a decrease in m g h, As the ball is accelerating due to gravity, at 9.81m/s. ", " My husband and son came with me for the tour. Based on your gathered information, make an educated guess about what types of things affect the system you are working with. This is a sample on how to write the results, conclusion and make charts. This will hopefully discount any anomalies automatically and leave us with three accurate and reliable results. To a wider range of results i.e. Dependable controls are sometimes very hard to develop. 7. 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. The first thing to check is how you are making your measurements. ball bounced 6 inches. WebHave them list all the variables they think will affect ball bounce. , v is greater therefore KE is greater by a larger amount). When the ball collides with the floor, the ball becomes deformed. Conveniently enough, this fraction of returned energy is nearly independent of how much energy the ball had to begin with. It was difficult to get down to the exact level of the blue tack seeing as it meant lowering your entire upper body in the short amount of time taken for the ball to hit the floor and rebound again to get your eye level from h, (where the blue tack was stuck, approximately). There you will find helpful links that describe different types of science projects, scientific method, variables, hypothesis, graph, abstract and all other general basics that you need to know. For each run, a different amount of change in the variable is used. 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. Stages of bouncing ball example, Panagi - StudySmarter Originals, Motion graphs of a bouncing ball, Panagi - StudySmarter Originals. 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. This is considered raw data since it has not been processed or interpreted yet. Therefore the coefficient to restitution = 0.7. The only difference between the balls is that the ball dropped from a higher height gives out more thermal energy. The higher the height from which the ball was dropped from, the higher the height to which it bounced. Find out about the physics of a dropped ball. If you are new in doing science project, click on How to Start in the main page. The balls are shown at rest, about to bounce back up. For example this is a sample explanation. This phenomenon is described by Newton's third law. Independent: - Type of surface the tennis ball is dropped on. For a falling object the Coefficient to restitution (C, ) is equal to the velocity squared as the object is travelling at as it leaves the floor (v, ) divided by the velocity squared as it hits the floor (v, If a ball is dropped in a vacuum. The moving ball gains kinetic energy when it bounces, and loses potential energy as it falls. The second stage is the point at which the ball decelerates, changes direction once it has reached the peak point, and starts falling to the ground. Adapted from Plangenhoef, Patterns of Human Motion. Specifically, you are tasked to determine: B.) A control variable is any factor that is controlled or held constant during an experiment. This list is called an experimental procedure. If a ball reaches terminal velocity at 20cm from the floor when dropped from 2m, it will reach terminal velocity at 10cm from the floor when dropped from 1.9m. It was decided that the first drop would start at 2m off the floor and then move down in intervals of 10cm to 10 cm off the floor. Dependent: - Height at which the tennis ball bounces. It pushes downward on the floor and the floor pushes upward on it. H is the height of the ball before it is dropped. 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. Questions lead to more questions, which lead to additional hypothesis that need to be tested. h1will start at 2m and then move down in intervals of 10cm to 10cm. Method: To set up the Our dependent variable was. The push which the ball receives from the floor at the moment of impact causes it to bounce up from the surface. These both support my prediction and show that my prediction was correct. 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. In this experiment there are FOUR VARIABLES. The ball rebounds to 38 percent of its previous height and continues to fall. For this reason, its also known as a controlled variable or a constant variable. 70% is retained. will differ from the height that the ball would have reached had it been dropped in a vacuum. Tape the ruler to the wall. If the drag is less the ball will fall faster and is less likely to reach its terminal velocity. In this project we will try to find out what factors affect the bounce of a dropped ball. What you have learned may allow you to answer other questions. The ball has reached its terminal velocity and cannot fall any faster (unless dropped in a vacuum). Experiment 2 is for testing the effect of air pressure. As velocity increases air resistance increases in proportion to the square of the velocity. 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. This would eliminate parallax error further. The last term is also known as the nth term of a geometric progression; n is the number of terms and a is the first term while Sn is the sum of the terms in the sequence as shown in the equation below. A geometric sequence is a progression where each term is related to the previous term, and it is related to the previous term by a number r, which is known as the common ratio of the sequence. or hold Ctrl and then use arrow keys to move the wave 0.01 second left or right. It was difficult to get down to the exact level of the blue tack seeing as it meant lowering your entire upper body in the short amount of time taken for the ball to hit the floor and rebound again to get your eye level from h1 to h2 (where the blue tack was stuck, approximately). Nie wieder prokastinieren mit unseren Lernerinnerungen. changing air density, temperature. 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 . 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. What is happening to the balls energy with each bounce? WebControlled Variables: -Golf ball -PVC piping -Angle of Ramp Our controlled variable was Manipulated Variable: -Release point -Distance ball bounces Our manipulated variables was: Dependent Variable: The distance in centimeters from bounce 1 to bounce 2. WebDrop the ball from the line between cinder blocks/bricks to make the measurements more accurate. The force that causes a ball to bounce is the reaction force described by Newton's third law of motion. This would mean that one could re-examine the height to which it bounced to and find it exactly instead of having to make a split second judgement which is not half as accurate. Also the difference between the force of air resistance acting upon a ball travelling at 1ms, and the force of air resistance acting upon a ball travelling at 2ms, is far smaller than the difference between the force of air resistance acting upon a ball travelling at 20ms, and the force of air resistance acting upon a ball travelling at 21ms, , the faster the velocity that the ball reaches. 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. Read books, magazines or ask professionals who might know in order to find out the factors that affect the movements of a dropped ball. Improvements that could be made to the experiment if future work was to be done: To provide additional relevant evidence I would conduct further work as follows; I would like to conduct the same experiment in a vacuum. The maximum height will have to be less than two meters as that is the maximum height that the equipment allows. The more KE that the ball possessed as it hit the floor, the more that was transferred into elastic potential energy and back into KE. It therefore hits more air particles each second and so the force of drag is bigger the faster the ball goes. WebThere are many different variables that would affect the bounce height of a ball. In this experiment you will drop a ball on a hard surface such as table and record the sounds it makes when it bounces using a computer and any sound recorder program. Upload unlimited documents and save them online. These two results were excluded when averages were being calculated and therefore the average variation between results used for calculating the average was even less than 3cm. It is a separate experiment, done exactly like the others. Sometimes variables are linked and work together to cause something. The motion of the ball can be split into different stages depending on the direction of the velocity vector; these stages are listed below. They identify variables to be changed, measured and controlled. Several new questions may have occurred to you while doing experiments. If the common ratio of the sequence is between 0 and 1, then the term r would approach zero. These conclusions help us confirm or deny our original hypothesis. 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 Its a good idea to bounce it on a level surface, and dont release from too great a height, or while bouncing, the ball will wander away from the sound recorder range. If possible, have a scientist review the procedure with you. In a real-life scenario, the ball will eventually stop moving due to external forces such as air friction. the initial height of your ball when you released it. This would allow the actual coefficient to restitution to be calculated. 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. Thus a typical ball bounces to 60% of its original height because it stores and returns 60% of the energy it had before the bounce. The most valuable resources for teachers and students. 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. 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. This is because the ball starts with more GPE. As there is more KE, more energy is converted into elastic potential energy, As there is more elastic potential energy, more energy is converted back into KE energy. 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. tennis and baseball) includes the CoR test. The balls leave the floor at the same speed with the same amount of KE and so both balls reach the same height and end up with the same amount of GPE at the top of their bounces. Constants: the same person takes all of the measurements, the same materials are used in every trial. Therefore the results are valid. Have all your study materials in one place. A thrown or batted ball may travel faster than the terminal speed, but it will experience a large drag force from the air which is greater than its weight. The mass of the ball will affect the height the ball bounces to because it affects the balls starting energy. The purpose of our lab was fulfilled. C) Frozen tennis balls will not bounce as high. If the ball is elastic in nature, the ball will quickly return to its original form and spring up from the floor. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. The CoRs apply to balls dropped or thrown at a rigid wooden surface. Schematic diagram of two balls dropped from different heights. Potential energy is the energy of position, and it depends on the mass of the ball and its height above the surface. it seems the ball is experiencing an oscillatory motion. It is also good to calculate the coefficient of restitution of your ball using the formula CoR = v/v = sqrt(h/h). Each of the following experiments tests a different hypothesis. 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. An experiment has several types of variables, including a control variable (sometimes called a controlled variable). 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. The coefficient of restitution is the ratio of the final to the initial relative speed between two objects after they collide. The first stage is where the ball bounces from the surface of the ground. The more particles per cubic meter, the more drag acting upon the ball. This denting extracts energy from the balls motion and stores much of it in the elastic surfaces of the floor and ball. Please note that many online stores for science supplies are managed by MiniScience. " WebControlled Variables: Bouncy ball used, surface bounced off of, technique in which ball was dropped (initial height was measured from base of ball). Vacuum pump, rigid plastic cylinder, two large rubber bungs to fit over the two ends of the plastic cylinder, table tennis ball, Two meter stick rulers. Drag is a squared function of velocity and therefore as the ball drops drag increases a greater amount each second. It tells us that the ball consistently bounced to half of its drop height. It was difficult to accurately measure the height of the bounce. 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. The last term can be the lowest height of the ball before it comes to an end as seen below. Hypothesis: Based on your gathered information, make an educated Following are some sample information that you may find: Everyone has played with balls that bounce, but few people truly understand the physics behind a bouncing ball. These are illustrated below. 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. Aim The aim of this experiment is to investigate the efficiency of a bouncing ball, and the factors which affect its efficiency. At 2ft, the basketball bounced 15 inches, the tennis ball bounced 12 inches, and the golf. 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. WebControl Variable: Simple Definition. Using the graph above, we can find the displacement by using the area under the graph, which is equal to the displacement. The bouncing ball example is an example used to study, A bouncing ball in an ideal scenario will continue this oscillatory motion. As gravity remains the same the amount of work acting on the ball remains the same (apart from slightly more air resistance due to the ball travelling faster and so hitting more air particles per second, but the effect of this is negligible) and the ball travels further before stopping. Course of Theoretical Physics : Mechanics (Course of Theoretical Physics), Engineering Mechanics Dynamics (11th Edition). Variables Independent variable = drop height Dependent variable = bounce height Controlled variables = ball, surface, measuring tool. Prior to the sample task, students investigated investigated forms of energy and energy transfers and transformations. For instance, air resistance would slow down the tennis ball much more when it is dropped from 100 m than when dropped from 1 m. This difference in impact speed would probably affect the bounce height. You measure this response, or record data, in a table for this purpose. An average will then be taken. Hence the formula for the sum of the infinite number of terms can be rewritten as seen here. Click Create Assignment to assign this modality to your LMS. You may now be able to understand or verify things that you discovered when gathering information for the project. It bounces off, changing the direction of motion and again reaching its maximum height. Therefore the ball goes higher. Finally, we need to multiply the distance found by 2, as one bounce of the ball includes both a rise and fall. If you follow the motion of either ball, youll realize that theres a moment halfway through its bounce when the ball is perfectly motionless in contact with the floor. WebPhysics Lab 1 - Bouncing Ball - Hardik December 2019 PDF Bookmark This document was uploaded by user and they confirmed that they have the permission to share it. In this experiment you will measure the bounce of a dropped ball for different release heights. 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. After the ball reaches terminal velocity, no more GPE is converted into KE is the ball cannot get any faster. 8. The ball did not appear to reach its terminal velocity which also supports my prediction. Discuss specifically how you developed your e and initial height values. Data table 2 indicates that on average tennis ball bounced to a lower height than it was dropped from. This slope tells us how bouncy the ball is. The third stage is the point at which the ball is momentarily deformed, and bounces off the ground in an upward direction until it reaches its maximum height. How well a ball bounces deals with its coefficient of restitution. \[S_{\infty} = \frac{\alpha(1-r^{\infty})}{1-r} = \frac{\alpha(1-0)}{1-r} \qquad S_{\infty} = \frac{\alpha}{1-r}\]. You may need to calculate the average of bounce height. As it falls, the ball converts energy stored in the force of gravitygravitational potential energyinto energy of motionkinetic energy. Apparatus:Clamp stand, meter rule 2, table tennis ball, desk. 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. The difference between the predicted height and the actual height will provide evidence as to how air resistance affects the flight of the ball. Locate the peaks and record the time for each peak. 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. During the preliminary experiment it was established that time was not an important factor that had to be taken into account when deciding how many different heights to drop the ball from and the interval between those heights. 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. WebRamp and ball, controlled study lab report. Does a ball bounce higher or lower in moon (Less Gravity), while all other conditions are constant? Even a specific ball may bounce different heights at different times or different locations. Choose one of the variables you listed in #4, and design an experiment to test it. Additional list of material can be extracted from the experiment section. h2= The distance between the bottom of the ball at the top of its arc after bouncing and the ground. Drag is a squared function of velocity and therefore as the ball drops drag increases a greater amount each second. Materials: -Carbon Paper -Goggles -Golf Balls What type of motion does a bouncing ball experience? Also its Gravitational Potential energy is decreasing because its height is decreasing. Is a bouncing ball an example of potential energy? 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. Be perfectly prepared on time with an individual plan. Height will be the variable that we will vary. As the ball is accelerating due to gravity, at 9.81m/s2it is constantly getting faster and therefore the drag force gets bigger and bigger. 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 means that the higher h. will differ from the height that the ball would have reached had it been dropped in a vacuum. At this level, science becomes even more interesting and powerful.8. Hence the final answer is: \(\text{Total distance} = 2 \cdot S_n = 2 \cdot 9.6 m= 19.2m\). To set up the 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. - Height at which the There are three types of variables: Controlled Variables: You can have as many controlled variables as you like. This is why it. 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. Measuring the height to which the ball bounced on subsequent bounces would be interesting, seeing if h. Will you pass the quiz? This is impossible. In my science fair experiment, the golf ball overall was the ball that bounced the highest. Lerne mit deinen Freunden und bleibe auf dem richtigen Kurs mit deinen persnlichen Lernstatistiken. 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. A ball falls from a height of 6 metres. While these variables are not the The bounce of a dropped ball has a direct relation with the release height. Using the geometric sequence for an infinite sequence and substituting the given values we get: \(S_{\infty} = 2 \cdot \frac{\alpha}{1-r} = 2 \cdot \frac{6m}{1-0.38} = 19.35 m\). We have a new and improved The surface onto which the ball is dropped upon will be kept the same. The terminal speed is the maximum speed reached when an object is dropped from a great height. Something about its situation then must determine its rebound, but what? (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.) Dependent variable is the height that the ball bounces. Dependent Variable: The height of the bounce. What purpose does a control serve? WebA) If a tennis ball is frozen, it won't bounce as high as one that is not frozen. WebWhat is a control? These polymers are tangled together and stretch upon impact. A ball falls from 8 metres and rebounds to 52 percent of its previous height. where g is the gravitational acceleration (9.8 m/ sec 2 at the Earths surface), and where h is the height of the object, measured with respect to any convenient zero- level. A) Find the total distance of travel until the ball hits the ground for the 5th time.

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