controlled variables in bouncing ball experiment

Dependent variable is the height that the ball bounces. 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. Identifying variables is necessary before you can make a hypothesis. You will then take your bounces and their respective time intervals to a spread sheet. 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. Is your hypothesis correct? Sometimes the designer of an experiment can miss the obvious. What does the motion of a bouncing ball look like? WebVariables: Height from which the ball is dropped Mass of the ball Material ball is made from External factors, i.e. Aim:To find out what affects the height to which a ball bounces. The acceleration on the ball is the acceleration of gravity, which acts downwards on the ball. So an imperfect ball loses some energy on each bounce. The terminal speed is the maximum speed reached when an object is dropped from a great height. At that instant, how does the ball know how high it should bounce? These equations allow us to predict how a change will affect the system without the need to do additional experiments. Then change the surface material by covering it with different material and repeat the test. What is the force that causes a ball to bounce? 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. 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. If the ball is elastic in nature, the ball will quickly return to its original form and spring up from the floor. As CR = h2/ h1it follows the gradient of the graph change in h2/ change in h1= CR. A series of experiments can be done by changing one variable a different amount each time. The force that causes a ball to bounce is the reaction force described by Newton's third law of motion. List three. Use a racquetball, a golf ball or any kind that bounces well and makes a nice crisp sound when it bounces. The ball weighs exactly 2.5g. Earn points, unlock badges and level up while studying. It will be important to keep track of what times go between what bounces. 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. If the common ratio of the sequence is between 0 and 1, then the term r would approach zero. By the time it reaches the floor, the ball is traveling quickly and it hits the floor hard. The ball is not performing a simple harmonic motion, as the acceleration is not proportional to the displacement from an equilibrium position. It is used to determine what the variable changed. 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. B) If I heat up a tennis ball it will bounce high. These balls do not bounce as well as balls with high air pressure. 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. 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. Constants: the same person takes all of the measurements, the same materials are used in every trial. This project guide contains information that you need in order to start your project. In the bouncing ball example, external forces such as air resistance are assumed to be zero. The following is a college level project, but some grade 9 to 12 students can also complete this with no problem. The reason for our error was that we thought that the tennis ball might be specially made to bounce to the same height. 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 h1 to h2 in order to obtain accurate results. Here, the motion of a real bouncing ball is shown. To set up the The moving ball gains kinetic energy when it bounces, and loses potential energy as it falls. Record the results in a table like this: Divide the bounce height of each row by the release height of the same row and write the result in the last column. As there is more GPE more energy is converted into KE (The ball is going faster, KE=1/2mv. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. The results of the experiment were obtained with a method that ensured that every drop was under similar conditions which ensured a fair test. Use the pencil and ruler to connect the incoming and outgoing trajectories of the marble to the point where the marble bounced off the wood. Using the geometric sequence for an infinite sequence and substituting the given values we get: \(S_{\infty} = 2 \cdot \frac{\alpha}{1-r} = 2 \cdot \frac{6m}{1-0.38} = 19.35 m\). Even a specific ball may bounce different heights at different times or different locations. 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. This is correct unless the ball shows signs of reaching terminal velocity. it seems the ball is experiencing an oscillatory motion. This list is called an experimental procedure. The coefficient of restitution is the ratio of the final to the initial relative speed between two objects after they collide. The longer it takes to stop, the higher it bounces to. How well a ball bounces deals with its coefficient of restitution. 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. GPE=Mass (kg) Gravitational Field Strength (N/Kg) Height (m). Adapted from Plangenhoef, Patterns of Human Motion. The distance along the ramp which the balls rolls. It is from calculations using recorded data that tables and graphs are made. Drop a ball from 1 foot off of the floor, slightly in front of a yardstick. Another experiment would be necessary to determine this for certain. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. Experiment 2 is for testing the effect of air pressure. 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. Hypothesis: If a tennis ball is dropped from a specific height then the ball will bounce to the same height. When the ball rebounds, its stored energy reappears and it leaps higher into the air than it would have had you dropped it a shorter distance. 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. Belowis the graph of h1against h2. Schematic diagram of two balls dropped from different heights. h1 = The distance between the bottom of the ball before it is dropped and the ground. The first graph is a displacement vs time graph. A bouncing ball is an example of oscillatory motion as the ball is oscillating about the equilibrium position. 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 Nie wieder prokastinieren mit unseren Lernerinnerungen. By registering you get free access to our website and app (available on desktop AND mobile) which will help you to super-charge your learning process. It shows that heights were recorded that exceeded the height that the ball would have reached had it been dropped in a vacuum. where m is the mass of the moving object, and v is the velocity of the moving object. All of the factors that could have affected the results that were uncontrollable could have produced variations between results. (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.) Find the total distance of travel until the ball hits the ground for the 8th time. 2. 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. The ball then rebounds: it undents and tosses itself up into the air to a good fraction of its original height. 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. When you hold a ball above a surface, the ball has potential energy. This therefore provides accurate and reliable results. 8. However, they only stretch for an instant before atomic interaction forces them back into their original, tangled shape and the ball shoots upward. WebAll experimental investigations involve variables. - Height at which the We have a new and improved If you are author or own the copyright of this book, please report to us by using this DMCA report form. The three trials at each height are then averaged, and the average bounce height is graphed versus the drop height. Several meter sticks for measuring the height of the bouncing ball or drawing a larger meter stick. The Graph on page 23 shows that all of the results were very close together. Is a bouncing ball an example of Newton's third law? At the lowest point, the ball has its minimum potential energy, and the velocity changes from negative to positive. 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. This is why it h2will 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. Calculating the coefficient to restitution of ball hitting the floor: The coefficient to restitution can be found out from a graph of h1against h2. The bounce of a dropped ball has a direct relation with the air pressure inside the ball. Yes, as elastic potential energy causes the ball to bounce off the ground and is converted into kinetic energy once the ball is in the air, causing it to move. Temperature will not affect the balls bounce either as the experiment will be conducted at room temperature, thus not allowing the floor to get cold and in doing so alter its affect upon the ball on impact. A) Using the graph above, find the displacement of the ball at 50 seconds. 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. If the mass of the ball is heavier the weight is heavier (weight = mg) and downward force acting upon the ball is greater as well. 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.