controlled variables in bouncing ball experiment
Create the most beautiful study materials using our templates. Find out about the physics of a dropped ball. We have a new and improved The formula for gravitational potential energy is PE = mgh where m is the mass of the ball measured in kg, g is the gravitational acceleration constant of 9.8 m/se c2 , and h is the height of the ball in m. As the ball falls through the air, the potential energy changes to kinetic energy. The equipment necessary to generate these conditions was not available and as a result the results obtained were not one hundred percent accurate. 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. Working out the variation in results shows how accurate the experiment was. 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. For testing air pressure you will need one ball that is inflatable such as a basketball ball. What Is The Control Variable In The Bouncing Ball Experiment? his the height of the balls bounce. Hypothesis: Based on your gathered information, make an educated The ball rebounds to 72 percent of its previous height and continues to fall. Identifying variables is necessary before you can make a hypothesis. More thermal energy is also produced. 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. 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. Therefore the heavier the ball is, the faster its terminal velocity. The total energy of the system remains the same; the potential energy changes to kinetic energy, but no energy is lost. Kinetic energy is energy of motion. WebOn 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. Our lab group was able to determine the relationship between drop height and bounce height. The motion of the ball can be described using velocity, displacement, and acceleration graphs, or geometric sequences. 1. The balls finish up with the same amount of energy and the only energy given out is thermal energy. 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. 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. Readings: Carrying out an investigation A ball that is dropped in air however is subjected to air resistance which affects the height to which it bounces. Using the trends in your experimental data and your experimental observations, try to answer your original questions. Create and find flashcards in record time. Hypothesis: If a tennis ball is dropped from a specific height then the ball will bounce to the same height. 3. 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. At the terminal speed, the drag force = the gravitational force. 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). This means that the faster that the ball travels the larger the force of air resistance upon it. This was when the ball was falling in air. WebControl Variable: Simple Definition. Bouncing Ball Experiment 15 inches, and the golf ball bounced 26 inches. CoR = coefficient of restitution = (speed after collision)/(speed before collision). 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. The example of the bouncing ball is used to study projectile motion in mechanics. Use a racquetball, a golf ball or any kind that bounces well and makes a nice crisp sound when it bounces. Is the measurement method questionable or unreliable? Problem: Hypothesis: Experiment: The Graph on page 23 shows that all of the results were very close together. 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. The last stage is the point at which the ball has reached its maximum displacement, decelerates, and changes the direction of motion from upwards to downwards. This would allow one to find the terminal velocity of the ball. WebThere are many different variables that would affect the bounce height of a ball. 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. The force that causes a ball to bounce is the reaction force described by Newton's third law of motion. Earn points, unlock badges and level up while studying. 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. Make a step-by-step list of what you will do to answer each question. An elastic surface such as rubber and a very hard surface such as concrete will result the highest bounce level. Therefore the coefficient to restitution = 0.7. Preparation: Draw a ruler with high visibility on a roll of paper about 8 inches wide and 6 feet tall. This will hopefully discount any anomalies automatically and leave us with three accurate and reliable results. 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. Summary of task. Aim:To find out what affects the height to which a ball bounces. Belowis the graph of h1against h2. 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. The higher the height from which the ball was dropped from, the higher the height to which it bounced. 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. Controlled Variable Data table 2 indicates that on average tennis ball bounced to a lower height than it was dropped from. C) Frozen tennis balls will not bounce as high. WebVariables: Height from which the ball is dropped Mass of the ball Material ball is made from External factors, i.e. Bouncing Ball 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. B (81%) Synonyms. The slope of the line in graph 1 was found to be 0.5. Use the same point on the ball (top) or (bottom) when judging both the height of the drop and the height of the bounce. The first stage is where the ball bounces from the surface of the ground. The answer lies in how far the ball has dented inward due to its collision with the floor. The terminal speed is the maximum speed reached when an object is dropped from a great height. 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. If the common ratio of the sequence is between 0 and 1, then the term r would approach zero. 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. The mass of the ball will affect the height the ball bounces to because it affects the balls starting energy. Variables - The Tennis ball experiment The acceleration on the ball is the acceleration of gravity, which acts downwards on the ball. Is a bouncing ball an example of potential energy? Something about its situation then must determine its rebound, but what? A ball falls from a height of 6 metres. This is repeated three times at 5 different heights. However the conditions were kept the same for each drop of the ball. 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. WebThere are many different variables that would affect the bounce height of a ball. 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. List three. ThatQuiz At that instant, how does the ball know how high it should bounce? Averages are more reliable than using one result as they take into account variation between results. It bounces off, changing the direction of motion and again reaching its maximum height. If you are using windows sound recorder program, you can view the recorded waves with an accuracy of 0.01 second. WebControl variables, also known as controlled variables, are properties that researchers hold constant for all observations in an experiment. 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. Calculating the coefficient to restitution of ball hitting the floor: The coefficient to restitution can be found out from a graph of h1against h2. Additionally we were able to practice reading a lab, taking data and making a graph. There are three types of variables: Controlled Variables: You can have as many controlled variables as you like. 2. Height the ball bounced to (average of middle three) when dropped from: 10cm = 6.7 6.7 = 66% of 10 (to the nearest percent), 20cm = 14.0 14.0 = 70% of 20 (to the nearest percent), 30cm = 22.3 22.3 = 74% of 30 (to the nearest percent). Aim The aim of this experiment is to investigate the efficiency of a bouncing ball, and the factors which affect its efficiency. We felt the magic immediately. It could also be a written statement of what occurred during experiments. 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. Is a bouncing ball an example of Newton's third law? Ball_Bounce - West Virginia University \[S_{\infty} = \frac{\alpha(1-r^{\infty})}{1-r} = \frac{\alpha(1-0)}{1-r} \qquad S_{\infty} = \frac{\alpha}{1-r}\]. The three trials at each height are then averaged, and the average bounce height is graphed versus the drop height. Finally, we need to multiply the distance found by 2, as one bounce of the ball includes both a rise and fall. The more KE the ball leaves the floor with the longer it takes to stop due to the force of gravity and return back to the floor again. Its 100% free. Set individual study goals and earn points reaching them. This is a sample on how to write the results, conclusion and make charts. What you have learned may allow you to answer other questions. Dropping a ball from different heights Dropping a ball from different heights could affect This means that the faster that the ball travels the larger the force of air resistance upon it. 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? This denting extracts energy from the balls motion and stores much of it in the elastic surfaces of the floor and ball. Upload unlimited documents and save them online. Therefore any change to the height from which the ball starts with affects the height to which it bounces to. It goes back to its initial vertical position after a period of time. The coefficient to restitution can be found out from a graph of, it follows the gradient of the graph change in h. . As the ball has less KE and is travelling slower it becomes stationary faster at the top of its arc. 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. Stages of bouncing ball example, Panagi - StudySmarter Originals, Motion graphs of a bouncing ball, Panagi - StudySmarter Originals. Therefore the height that it reaches is less high. 1. 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. This is because as the ball goes faster it passes through a greater volume of air each second. What purpose does a control serve? You will be able to precisely measure the time intervals between bounces. Constants: the same person takes all of the measurements, the same materials are used in every trial. The results of the experiment were obtained with a method that ensured that every drop was under similar conditions which ensured a fair test. The procedure allowed me to observe the affects of the height from which a table tennis ball was dropped from upon the height to which it bounced. Once the ball hits the ground, its displacement is momentarily zero. 7. The ball did not appear to reach its terminal velocity which also supports my prediction. What is the velocity of the ball at the point of maximum height? 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. changing air density, temperature The surface onto which the ball The ball rebounds to 38 percent of its previous height and continues to fall. These both support my prediction and show that my prediction was correct. Reverse Engineering: Ball Bounce Experiment Dependent Variable: The height of the bounce. Control variable - Wikipedia Without a control you cannot be sure that changing the variable causes your observations. Therefore the ball goes higher. GPE also changes as the ball falls. (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.) 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. ", " My husband and son came with me for the tour. 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. In the bouncing ball example, external forces such as air resistance are assumed to be zero. A series of experiments that includes a control is called a controlled experiment.. 30% of the energy that the ball hits the floor wit is lost. ball If the coefficient to restitution = 0.7, a ball dropping from h1in a vacuum would reach the height of 0.7 h1 after bouncing. Apparatus:Clamp stand, meter rule 2, table tennis ball, desk. 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. Yes, as the ball receives a force from the ground due to collision, which causes the ball to bounce off the ground. 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. This will be a table tennis ball. Writing Quality. Its height gradually decreases until it eventually stops moving. Create beautiful notes faster than ever before. What Effects the Bounce of a Dropped Ball Kinetic energy means energy associated with motion. WebWhat is a control? Variables Independent variable = drop height Dependent variable = bounce height Controlled variables = ball, surface, measuring tool. For each height repeat the test 3 to 5 times and record the most reliable result. This calculation is shown in the data analysis section above. Therefore the height the ball bounces will be proportional to the height that the ball is dropped from up to a certain point, where the ball begins to show signs of reaching its terminal velocity before it reaches the ground. Grades: Preschool and K-2 Length of Lesson: Approximately 45 minutes Related Video: The Hawk Factor episode Learning Goals: When a ball drops in air there is air resistance to which the ball loses energy in the form of thermal energy. Why if you drop a ball from say 2 meters does it bounce higher than a ball dropped from 1 meter? 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. My hypothesis is based on my observation of balls that are not well inflated. A) scientific method. the Scientific Method The ball then rebounds: it undents and tosses itself up into the air to a good fraction of its original height. Schematic diagram of two balls dropped from different heights. Balls Bouncing Off of Surfaces Method:The apparatus will be set up as shown: H is the height of the ball before it is dropped. Measure the height the ball reaches after the first bounce and record. This slope tells us how bouncy the ball is. where m is the mass of the moving object, and v is the velocity of the moving object. 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. Locate the peaks and record the time for each peak. The purpose of our lab was fulfilled. They identify variables to be changed, measured and controlled. Report DMCA Overview Hence the formula for the sum of the infinite number of terms can be rewritten as seen here. It shows that heights were recorded that exceeded the height that the ball would have reached had it been dropped in a vacuum. 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 A bouncing ball is an example of oscillatory motion as the ball is oscillating about the equilibrium position. The energy that the ball hits the floor with is kinetic energy. These are parts of the experiment that you try to keep constant throughout an experiment so that they won't interfere with your test. Factors affecting ball bounce As a general rule, when the ball is travelling in the positive direction (upwards), the velocity can be assumed to be positive. For a perfectly elastic bounce (the ultimate super ball), e =1; and for an inelastic bounce (like clay dropping on the floor), e =0. This also proves the accuracy of the experiment. As energy cannot be created or destroyed it follows that the energy must have come from the energy that the ball possesses. 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. Does a ball bounce higher or lower in moon (Less Gravity), while all other conditions are constant? For this reason, its also known as a controlled variable or a constant variable. Dribbling a Basketball and Transfer of Energy | Science Project D) If I freeze a tennis ball, then it will not bounce as high. An average will then be taken. 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. 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. Read books, magazines or ask professionals who might know in order to find out the factors that affect the movements of a dropped ball. 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. If the ball is elastic in nature, the ball will quickly return to its original form and spring up from the floor. We felt the magic immediately.". Bouncing Ball Experiment Our simple experiment is to drop a ping pong ball weighed at 3 grams from a height of 1 metre then 90cm, 80cm, 70cm, This means that if a heavier ball is to be used then it will need to be dropped from higher to reach its terminal velocity. Bounce/Release is the relation of bounce height to the release height. The maximum height will have to be less than two meters as that is the maximum height that the equipment allows. The ball weighs exactly 2.5g. It will be vinyl tiling. What factors affect the bounce of a dropped ball? Do you think e is constant for your ball? Find the total distance of travel until the ball hits the ground for the 8th time. A) Using the graph above, find the displacement of the ball at 50 seconds. The CoRs apply to balls dropped or thrown at a rigid wooden surface. In my science fair experiment, the golf ball overall was the ball that bounced the highest. Find sections related to potential energy, elasticity and springs. Dependent variable is the height that the ball bounces. This produces a different amount of response in the system. This is correct unless the ball shows signs of reaching terminal velocity. The following is a college level project, but some grade 9 to 12 students can also complete this with no problem. 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. Be perfectly prepared on time with an individual plan. 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. Why or why not? 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 why it. This phenomenon is described by Newton's third law. Your bibliography must contain sources that are available to you (at your school or local library). 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. Stop procrastinating with our study reminders.Merivale Hemmes Biography, Problemas De Pareja Por Hijos De Otro Matrimonio, Karen And Ron I Survived, Articles C