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). These equations allow us to predict how a change will affect the system without the need to do additional experiments. The bounce of a dropped ball has a direct relation with the release height. In this experiment there are FOUR VARIABLES. In a real-life scenario, the ball will eventually stop moving due to external forces such as air. The process of obtaining information by using the senses is called a/an. The moving ball gains kinetic energy when it bounces, and loses potential energy as it falls. However, they only stretch for an instant before atomic interaction forces them back into their original, tangled shape and the ball shoots upward. This is because the ball starts with more GPE. This would allow one to find the terminal velocity of the ball. It therefore hits more air particles each second and so the force of drag is bigger the faster the ball goes. 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. The slope of the line in graph 1 was found to be 0.5. The experiment was conducted as the method (below) states. A bouncing ball follows a projectile motion which is moving near the surface of the earth in a curved path due to the effect of gravity. The ball did not appear to reach its terminal velocity which also supports my prediction. Soccer Science Fair Project: Air Pressure & Distance - Education 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. Material that you may test are: Carpet, Rubber matte, ply wood, sponge, Styrofoam, another 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. It is also good to calculate the coefficient of restitution of your ball using the formula CoR = v/v = sqrt(h/h). The relative height of the bounce should be h/h = CoR2 = 0.72 = 0.49. WebControl variables, also known as controlled variables, are properties that researchers hold constant for all observations in an experiment. 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. The first graph is a displacement vs time graph. Bouncing balls experiment It will be vinyl tiling. An average will then be taken. 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. Based on your gathered information, make an educated guess about what types of things affect the system you are working with. What factors affect the bounce of a dropped ball? The ball pushes on the floor and the floor pushes back on the ball, causing it to rebound. 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 h1 to h2 in order to obtain accurate results. WebControlled Variables: Bouncy ball used, surface bounced off of, technique in which ball was dropped (initial height was measured from base of ball). B (81%) Synonyms. If the coefficient to restitution = 0.7, a ball dropping from h1in a vacuum would reach the height of 0.7 h1 after bouncing. (The upward direction was assumed to be positive in this example. Also its Gravitational Potential energy is decreasing because its height is decreasing. Controlled variables are air temperature, air flow, air pressure where you perform your tests. 2. 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. = The distance between the bottom of the ball at the top of its arc after bouncing and the ground. 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. Once the ball hits the ground, its displacement is momentarily zero. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. Conveniently enough, this fraction of returned energy is nearly independent of how much energy the ball had to begin with. H is the height of the ball before it is dropped. Is a bouncing ball an example of Newton's third law? 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. Variables are D) If I freeze a tennis ball, then it will not bounce as high. At 2ft, the basketball bounced 15 inches, the tennis ball bounced 12 inches, and the golf. 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. Bounce/Release is the relation of bounce height to the release height. Yes, as the ball receives a force from the ground due to collision, which causes the ball to bounce off the ground. Upload unlimited documents and save them online. This means it will be travelling the same speed when it hits the ground. For an infinite number of turns, another geometric sequence formula can be used. Report DMCA Overview I called School Time and my husband and son came with me for the tour. This will be repeated five times, possibly more (for accuracy), for each height and the top and bottom results will be discounted. A control variable is any factor that is controlled or held constant during an experiment. What are the variables in the ramp experiment? That height fraction is equal to the fraction of energy that the ball successfully stored and returned during its bounce. Questions lead to more questions, which lead to additional hypothesis that need to be tested. A ball falls from a height of 3 metres. The terminal speed is the maximum speed reached when an object is dropped from a great height. When raw data gets processed mathematically, for example, it becomes results. ", " My husband and son came with me for the tour. A controlled variable is one which the researcher holds constant (controls) during an experiment. The sum of the two, mechanical energy, stays the same ( is conserved.). The ball is not performing a simple harmonic motion, as the acceleration is not proportional to the displacement from an equilibrium position. Hence the formula for the sum of the infinite number of terms can be rewritten as seen here. What type of motion does a bouncing ball experience? If the KE is the same as they hit the ground the energy stored in the ball as elastic potential energy will be the same also. WebWhat is a control? 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. These conclusions help us confirm or deny our original hypothesis. External factors, i.e. 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. A totally accurate experiment would have a variation between results equal to zero however an experiment that is totally accurate needs to be conducted under conditions where air pressure and temperature remained constant, error produced by the ball falling on different parts of the linoleum floor tile (which was not totally even and thus produces inaccurate results) and human error removed by dropping the ball onto a uniform surface and using machinery to record the height to which the ball bounced to. Constants are the release height, the bouncing surface, the type and the size of the ball. So an imperfect ball loses some energy on each bounce. Draw a graph of bounce height Vs drop height. Ramp and ball, controlled study lab report Ball Five repeats were done as it was deemed that an average of the middle three was reasonably accurate. Why if you drop a ball from say 2 meters does it bounce higher than a ball dropped from 1 meter? The push which the ball receives from the floor at the moment of impact causes it to bounce up from the surface. It tells us that the ball consistently bounced to half of its drop height. Discuss specifically how you developed your e and initial height values. WebRamp and ball, controlled study lab report. This denting extracts energy from the balls motion and stores much of it in the elastic surfaces of the floor and ball. Problem: Hypothesis: Experiment: 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 starts at height h, No energy is lost when the ball is falling; there is no air resistance, so no Thermal Energy is produced. ball The acceleration on the ball is the acceleration of gravity, which acts downwards on the ball. It provided me with five repeats so that the maximum and minimum results could be discounted and a reliable average could be taken. Use the same point on the ball (top) or (bottom) when judging both the height of the drop and the height of the bounce. It could also be a written statement of what occurred during experiments. Physics Ia on Bouncing Ball 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. Figure 1. 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. Dependent variable is the height that the ball bounces. Is a bouncing ball an example of simple harmonic motion? Bouncing Ball Removing the maximum and minimum results and taking an average of the middle three results also provided more accurate results. In this experiment you will measure the bounce of a dropped ball for different release heights. 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 ball rebounds to 72 percent of its previous height and continues to fall. These both support my prediction and show that my prediction was correct. Method: To set up the If you choose to study on any other variable, following are samples of hypothesis. 70% is retained. Grades: Preschool and K-2 Length of Lesson: Approximately 45 minutes Related Video: The Hawk Factor episode Learning Goals: This would eliminate parallax error further. Identifying variables is necessary before you can make a hypothesis. A decrease in h1, assuming g and m stay constant, results in a decrease in m g h1which results in a decrease in GPE. The surface onto which the ball is dropped upon will be kept the same. The total energy of the system remains the same; the potential energy changes to kinetic energy, but no energy is lost. Gravitational potential energy means energy that an object has based on where it is located in a gravitational field. Air pressure will affect the balls fall slightly as the concentration of air particles per cubic meter varies with air pressure. 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. The more particles per cubic meter, the more drag acting upon the ball. where m is the mass of the moving object, and v is the velocity of the moving object. When you hold a ball above a surface, the ball has potential energy. 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. Nie wieder prokastinieren mit unseren Lernerinnerungen. \[S_{\infty} = \frac{\alpha(1-r^{\infty})}{1-r} = \frac{\alpha(1-0)}{1-r} \qquad S_{\infty} = \frac{\alpha}{1-r}\]. I do not believe that any ball will reach terminal velocity in this experiment seeing as the maximum height that they can be dropped from is 2m and, as the ball is quite smooth, I do not believe that it will have enough time to accelerate to its terminal velocity before it hits the floor. You are NOT going to perform this experiment. 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. 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. 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. 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. Controlled Variable So if we double the air pressure, we will get double bounce height. The CoRs apply to balls dropped or thrown at a rigid wooden surface. 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. Bouncing balls AT (Year 8 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 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. 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. For example, we could have used a ruler on the top to help us read how high up the tennis ball bounced, and we could have made sure the partner taking measurements did so from a consistent height. Stop procrastinating with our smart planner features. 30% of the energy that the ball hits the floor wit is lost. 1. CoR = coefficient of restitution = (speed after collision)/(speed before collision). 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. The motion of the ball can be split into different stages depending on the direction of the velocity vector; these stages are listed below. The Graph on page 23 shows that all of the results were very close together. 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 means that the higher h1the more h2will differ from the height that the ball would have reached had it been dropped in a vacuum. 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. 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. \(Area = \frac{1}{2} \cdot base \cdot length\), \(Area = 0.5 m \cdot 50 m \cdot 50 m = 1250 m^3\). About a foot above the table top is plenty. This is Newtons Third Law of Motion- for every action there is an equal and opposite reaction. What factors affect the bounce of a dropped 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. The bounce of a dropped ball has a direct relation with the air pressure inside the 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. There are three types of variables: Controlled Variables: You can have as many controlled variables as you like. 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. At this level, science becomes even more interesting and powerful.8. The ball did not reach terminal velocity however as it did not have enough time to accelerate to its terminal velocity. These polymers are tangled together and stretch upon impact. WebVariables. For instance result 3 from 200cm was an anomaly but was not taken into account when taking the average of the middle three. Once the drag force equals the gravitational force all forces are equal and acceleration stops. Click Create Assignment to assign this modality to your LMS. Yes, as the ball is oscillating about the equilibrium position (in height) and goes back to its initial position after a period of time. 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. 1. These are illustrated below. 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. We felt the magic immediately. To set up the 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. 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 average variation between results was 3cm. This experiment would provide me with more results that are relevant to the experiment that I have already conducted. 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. A series of experiments that includes a control is called a controlled experiment.. These stages can also be represented graphically using three plots including a displacement, velocity, and acceleration vs time graph. What does the motion of a bouncing ball look like? 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: You will next need to record your bounces and their respective times. The ball has reached its terminal velocity and cannot fall any faster (unless dropped in a vacuum). 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. A) scientific method. Also it will affect its bouncing properties. Possible sources of error include several types of measurement errors. WebDrop the ball from the line between cinder blocks/bricks to make the measurements more accurate. h1 = The distance between the bottom of the ball before it is dropped and the ground. 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. 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. My hypothesis is based on my observation of balls that are not well inflated. This motion can be described using a geometric sequence, as the height of the ball after each bounce depends on the initial height from which the ball fell. Repeat this test from 2 ft, 3 ft, and 1/2 ft. Do this test for each ball and record data. What is the velocity of the ball at the point of maximum 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. Based on these trends, we can draw conclusions about the system under study. 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. 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. Your assistant will record the bounce. 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 exact interval will be determined after the preliminary experiment, as will the number of heights that the ball will be dropped from. Method:The apparatus will be set up as shown: H is the height of the ball before it is dropped. Make a step-by-step list of what you will do to answer each question. ball bounced 6 inches. Controlling Variables Part 1 ( Video ) | Chemistry | CK-12 Foundation 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. This applies to a ball falling in a vacuum. This is correct unless the ball shows signs of reaching terminal velocity. Measure the height the ball reaches after the first bounce and record. The more energy that the ball possessed before being dropped, the more energy was converted into KE while the ball fell. 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. An elastic surface such as rubber and a very hard surface such as concrete will result the highest bounce level. However the conditions were kept the same for each drop of the ball. The ball then rebounds: it undents and tosses itself up into the air to a good fraction of its original height. The energy chain is as follows: Therefore as energy cannot be created or destroyed the energy the ball starts with must be directly proportional to the energy the ball finishes with, at the top of its bounce, and so if the ball starts with more energy it must therefore finish with more. The acceleration due to gravity causes the ball to change direction and start moving downwards at stage 2. In this project we will try to find out what factors affect the bounce of a dropped ball. Then when dropping the ball again eye level will be kept level with the blue tack thus avoiding parallax errors.