You may need to calculate the average of bounce height. A control is the variable that is not changed in the experiment. Our dependent variable was. For an experiment to give answers you can trust, it must have a control. A control is an additional experimental trial or run. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. 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. C) Frozen tennis balls will not bounce as high. In this experiment the only variable that we modify is the type or flexibility of bounce surface and we keep all other variables unchanged. \(E_{pot} = E_{kin} \cdot m \cdot g \cdot h = \frac{1}{2} \cdot m \cdot v^2\). Hold the ball at 6 feet height and release it on a hard concrete surface. These conclusions help us confirm or deny our original hypothesis. When you drop a ball from a greater height, it has more kinetic energy just before it hits the floor and stores more energy during the bounceit dents farther as it comes to a stop. This is in accordance with Newton's second law. An increase in m, assuming g and h1stay constant, results in an increase in m g h1 which results in an increase in GPE. However the conditions were kept the same for each drop of the ball. Several balls, medium-sized super balls, hollow rubber balls, solid rubber balls, tennis balls, golf balls, baseballs, and whatever other types of balls are available. Materials: -Carbon Paper -Goggles -Golf Balls changing air density, temperature The surface onto which the ball On a molecular level, the rubber is made from long chains of polymers. Set individual study goals and earn points reaching them. 7. Preparation: Draw a ruler with high visibility on a roll of paper about 8 inches wide and 6 feet tall. 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. Design an experiment to test each hypothesis. When a ball drops in air there is air resistance to which the ball loses energy in the form of thermal energy. Do you think e is constant for your ball? When the ball travels in the negative direction (downwards), the velocity can be assumed to be negative. Is the measurement method questionable or unreliable? At the point of maximum height, the ball momentarily has zero velocity, and the direction of velocity is changing from positive to negative. Newton's third law states that every force or action has an equal and opposite reaction. 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. It was difficult to accurately measure the height of the bounce. Many questions are related. Specially look for parts that discuss the gas pressure and physical properties of gases. My hypothesis is based on my observation of balls that are not well inflated. The higher the height from which the ball was dropped from, the higher the height to which it bounced. Several smooth hard flat horizontal surfaces suitable for bouncing ballsfloors, lab tables, sidewalks, and the like. It is used to determine what the variable changed. Once the ball hits the ground, its displacement is momentarily zero. So an imperfect ball loses some energy on each bounce. Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically. 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. At this level, science becomes even more interesting and powerful.8. At that instant, how does the ball know how high it should bounce? 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). This will hopefully discount any anomalies automatically and leave us with three accurate and reliable results. For a perfectly elastic bounce (the ultimate super ball), e =1; and for an inelastic bounce (like clay dropping on the floor), e =0. In reality, the ball experiences damping, where it loses potential energy and kinetic energy as it falls. The force that is received by the ball from the ground from the collision causes it to rebound, which converts the potential energy to kinetic energy. Please note that many online stores for science supplies are managed by MiniScience. " 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. Measuring the height to which the ball bounced on subsequent bounces would be interesting, seeing if h. WebRamp and ball, controlled study lab report. This is impossible. Discuss specifically how you developed your e and initial height values. WebControl variables include the size of pots, the type of soil and the position in a room. The Bounce/Release is the relation of bounce height to the release height. Controlled variables are air temperature, air flow, air pressure where you perform your tests. 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. 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. 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. Hypothesis: If a tennis ball is dropped from a specific height then the ball will bounce to the same height. 1. 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. You measure this response, or record data, in a table for this purpose. You are NOT going to perform this experiment. The longer it takes to stop, the higher it bounces to. What is the velocity of the ball at the point of maximum height? (The upward direction was assumed to be positive in this example. Here, the motion of a real bouncing ball is shown. 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. 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. You may now be able to understand or verify things that you discovered when gathering information for the project. 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. 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. 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. No, the bouncing ball example is not an example of simple harmonic motion. Find the infinite distance of travel. Everything you need for your studies in one place. 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. Then change the surface material by covering it with different material and repeat the test. What purpose does a control serve? It pushes downward on the floor and the floor pushes upward on it. Method:The apparatus will be set up as shown: H is the height of the ball before it is dropped. As the ball has less KE and is travelling slower it becomes stationary faster at the top of its arc. The bounce of a dropped ball has a direct relation with the release height. Projectile motion is the motion of objects that are moving near the surface of the earth in a curved path due to the effect of gravity. It provided me with five repeats so that the maximum and minimum results could be discounted and a reliable average could be taken. This did not happen in my experiment however. When a player dribbles a basketball, as Kobe Bryant does here on the 2012 U.S. men's Olympic team, the ball actually transfers some of its energy on each 8. use four meter sticks and go right the way up to four meters. This can either be assumed and chosen, or it can be stated in a question.). 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. The results of the experiment were obtained with a method that ensured that every drop was under similar conditions which ensured a fair test. For example this is a sample explanation. WebThe scientific method consists of five steps: -Observation/research: The first step is to research and collect as much background information on your chosen question as you can. 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. of the users don't pass the Bouncing Ball Example quiz! If the ball is elastic in nature, the ball will quickly return to its original form and spring up from the floor. 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. At 3ft, the basketball bounced 20 inches, the tennis ball bounced. Sometimes variables are linked and work together to cause something. This is correct unless the ball shows signs of reaching terminal velocity. The purpose of this project is to find out what factors affect the bounce of a dropped ball. You can drop the ball from your hand or you can make a stopper for the ball to hold it only from the sides with a little pressure. 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. Variables Independent variable = drop height Dependent variable = bounce height Controlled variables = ball, surface, measuring tool. Why or why not? 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. A ball falls from a height of 6 metres. Several meter sticks for measuring the height of the bouncing ball or drawing a larger meter stick. 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? The ball did not reach terminal velocity however as it did not have enough time to accelerate to its terminal velocity. The same square of tiling will be used throughout the experiment so that inconsistencies between different floor tiles do not affect results. The terminal speed is the maximum speed reached when an object is dropped from a great height. More thermal energy is also produced. It shows that heights were recorded that exceeded the height that the ball would have reached had it been dropped in a vacuum. Therefore the energy that the ball hits the floor with = mh, The proportion of energy lost when ball hits the floor = The Coefficient to the restitution of the two objects (C, All of the energy that the ball leaves the floor with is converted back into GPE, If dropping a ball in a vacuum all you need to know in order to know how high the ball will bounce to is h, can be found out by looking at a graph, the gradient, as a percentage of 1 gives the amount of energy conserved and therefore C. The clamp stand will be clamped down to the desk using a g-clamp to prevent it falling over and causing possible injuries. WebHave them list all the variables they think will affect ball bounce. 30% of the energy that the ball hits the floor wit is lost. For a dropped ball, the total mechanical energy is defined as the sum of its kinetic energy and its gravitational potential energy. Research questions pose a question about the Sign up to highlight and take notes. B (81%) Synonyms. 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. This help to greatly increase the accuracy of the experiment. Why if you drop a ball from say 2 meters does it bounce higher than a ball dropped from 1 meter? This will be repeated five times, possibly more (for accuracy), for each height and the top and bottom results will be discounted. Summary of task. These are parts of the experiment that you try to keep constant throughout an experiment so that they won't interfere with your test. Repeat this test from 2 ft, 3 ft, and 1/2 ft. Do this test for each ball and record data. 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). The distance along the ramp which the balls rolls. Air density will not change enough to affect the flight of the ball seeing as all the results will be collected during a brief period on one day. will start at 2m and then move down in intervals of 10cm to 10cm. 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. For an infinite number of turns, another geometric sequence formula can be used. This will be a table tennis ball. 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 means that the higher h. will differ from the height that the ball would have reached had it been dropped in a vacuum. What type of motion does a bouncing ball experience? Identify your study strength and weaknesses. All of the factors that could have affected the results that were uncontrollable could have produced variations between results. The example of the bouncing ball is used to study projectile motion in mechanics. So, we equate the potential energy and the kinetic energy. The format you use to write your bibliography may look like this: Are you ready for more advanced ball drop projects? The ball has reached its terminal velocity and cannot fall any faster (unless dropped in a vacuum). Use a racquetball, a golf ball or any kind that bounces well and makes a nice crisp sound when it bounces. Keep track of where you got your information from. Gravitational potential energy means energy that an object has based on where it is located in a gravitational field. 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. 2. h1 = The distance between the bottom of the ball before it is dropped and the ground. From this I am able to determine that the experiment was very accurate. Yes, as the ball is oscillating about the equilibrium position (in height) and goes back to its initial position after a period of time. The higher the ball goes, the more GPE it ends up with. Measure the height the ball reaches after the first bounce and record. It travels upwards towards its highest point. 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. It depends only on the elasticity of the ball itselfa super ball returns a large fraction while a beanbag returns a tiny fraction. Is a bouncing ball an example of oscillatory motion? This denting extracts energy from the balls motion and stores much of it in the elastic surfaces of the floor and ball. 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. WebA) If a tennis ball is frozen, it won't bounce as high as one that is not frozen. Choose one of the variables you listed in #4, and design an experiment to test it. The only difference is that no experimental variables are changed. 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 . This is because it is the easiest and quickest variable to alter. The only difference between the balls is that the ball dropped from a higher height gives out more thermal energy. What is the control variable in the bouncing ball experiment? WebVariables. Dependent variable is the height that the ball bounces. 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. When the ball collides with the floor, the ball becomes deformed. Your assistant will record the bounce. Lerne mit deinen Freunden und bleibe auf dem richtigen Kurs mit deinen persnlichen Lernstatistiken. It shows that heights were recorded that exceeded the height that the ball would have reached had it been dropped in a vacuum. 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. WebDrop the ball from the line between cinder blocks/bricks to make the measurements more accurate. Once the drag force equals the gravitational force all forces are equal and acceleration stops. The ball is not performing a simple harmonic motion, as the acceleration is not proportional to the displacement from an equilibrium position. 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. the initial height of your ball when you released it. This will be called the average of the middle three repeats. 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. However when the ball is dropped from a relatively low height, drag 0. WebBouncing Ball Experiment - Free download as Word Doc (.doc / .docx), PDF File (.pdf), Text File (.txt) or read online for free. In this project we will try to find out what factors affect the bounce of a dropped ball. A single experiment may contain many control variables. 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. You will next need to record your bounces and their respective times. To do that use the scroll button to start, then use arrow keys to move your wave 0.1 second left or right. 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. 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. This is Newtons Third Law of Motion- for every action there is an equal and opposite reaction. This project guide contains information that you need in order to start your project. 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. 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, 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. Create flashcards in notes completely automatically. The ball did not appear to reach its terminal velocity which also supports my prediction. The reason for our error was that we thought that the tennis ball might be specially made to bounce to the same height. Something about its situation then must determine its rebound, but what? Potential energy is the energy of position, and it depends on the mass of the ball and its height above the surface. Writing Quality. changing air density, temperature. Choose one of the variables you listed in #4, and design an experiment to test it. The coefficient of restitution is the ratio of the final to the initial relative speed between two objects after they collide. Sometimes the designer of an experiment can miss the obvious. 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. You are now ready to enter your data on a spread sheet and get to work. Prior to the sample task, students investigated investigated forms of energy and energy transfers and transformations. his the height of the balls bounce. This means it will be travelling the same speed when it hits the ground. 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. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Data Table 2: Average Bounce Height at Each Height: Graph 1: Height of Ball drop versus Height of ball bounce: Our data indicates that the hypothesis was incorrect. Now is the time to pull together what happened, and assess the experiments you did. What are the variables in the ramp experiment? In the bouncing ball example, external forces such as air resistance are assumed to be zero. 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. Working out the variation in results shows how accurate the experiment was. These stages are continuously repeated and shown in the sequence below. This produces a different amount of response in the system. This was when the ball was falling in air. Stop procrastinating with our smart planner features. The more energy that the ball possessed before being dropped, the more energy was converted into KE while the ball fell. A bouncing ball is an example of oscillatory motion as the ball is oscillating about the equilibrium position. The first graph is a displacement vs time graph. Stages of bouncing ball example, Panagi - StudySmarter Originals, Motion graphs of a bouncing ball, Panagi - StudySmarter Originals. Five repeats were done as it was deemed that an average of the middle three was reasonably accurate. 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. Procedure: One group member drops a tennis ball from a specific height, while the other group member notes how high the ball bounces. = The distance between the bottom of the ball before it is dropped and the ground. 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. Also the difference between the force of air resistance acting upon a ball travelling at 1ms-1 and the force of air resistance acting upon a ball travelling at 2ms-1 is far smaller than the difference between the force of air resistance acting upon a ball travelling at 20ms-1 and the force of air resistance acting upon a ball travelling at 21ms-1. The first thing to check is how you are making your measurements. Is a bouncing ball an example of simple harmonic motion? This means that the faster that the ball travels the larger the force of air resistance upon it. 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. As velocity increases air resistance increases in proportion to the square of the velocity. Dependent Variable: The Bounce (How height is the ball going to Bounce) because of the These inaccuracies could have been caused by external factors or parallax error even though efforts were made to avoid parallax error occurring - by dropping the ball one time that was not measured and placing a blob of blue tack onto the meter rule at the approximate height it bounced to. The mass is cancelled out in the above equation, and we re-arrange with respect to velocity. A) scientific method. Calculating the coefficient to restitution of ball hitting the floor: The coefficient to restitution can be found out from a graph of h1against h2. 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. it seems the ball is experiencing an oscillatory motion. Summarize what happened. This also proves the accuracy of the experiment. It therefore hits more air particles each second and so the force of drag is bigger the faster the ball goes. What factors affect the bounce of a dropped ball? 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 The positive and negative directions must be stated in each example. 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. Find sections related to potential energy, elasticity and springs. Be perfectly prepared on time with an individual plan. Variables are D (60%) Belowis the graph of h1against h2. The difference between the predicted height and the actual height will provide evidence as to how air resistance affects the flight of the ball. A controlled variable is one which the researcher holds constant (controls) during an experiment. This experiment would provide me with more results that are relevant to the experiment that I have already conducted. will differ from the height that the ball would have reached had it been dropped in a vacuum. 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. As there is more GPE more energy is converted into KE (The ball is going faster, KE=1/2mv. A ball falls from a height of 3 metres. It goes back to its initial vertical position after a period of time. For testing air pressure you will need one ball that is inflatable such as a basketball ball. Find the total distance of travel until the ball hits the ground for the 8th time. 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. The bounce of a dropped ball has a direct relation with the air pressure inside the ball.
controlled variables in bouncing ball experiment