a) Start with the video at the instant just after the gliders separate (just one frame after the end of collision). For each glider, set a ruler with the zero at the front edge of the glider, as shown in the screen shot below. Again, notice the thin gop between the hoops indicating the hoops just separated. Set the timer to zero. 25 pivot d) Run the video and measure the time each glider needs to travel 11 cm. Be accurate in matching the front edge of the gliders with the ruler marks! Record the time and distance in the table provided below. b) Record all your measurements in the table below and then complete it with velocity calculations. Record the distances in meters so the velocities are in m/s. We choose the positive direction to the right. Enter the velocity of the left glider after collision with negative sign since it's moving to the left, and the other two velocities with positive sign since they correspond to motions to the right. Make sure you enter the values using five significant digits.Elastic Collision Change LISP} % Change Momentum Calculations Left glider 0.021686 00090411 43.030727 4360109757 Right glider 0 0.03061TQ25 0030617925 200 Total Momentum 0.021686 0.02157? Calculate: the kinetic energy for each glider, before and after collision the total kinetic energy, before and after the collision The change AKE = (KEaer KEbEfm) in each KE calculated above The percentage change [AKEflKEaeimnxlDO in each KE calculated above Record the results in the table below. Enter the KE values using five significant digits and round off the percentages to two significant digits. Elastic Collision D (m) T (s) V (m/s) D (m) T (s) V (m/s) Velocity Measurements Before Before Before After After After Left glider 0.1 0.675 0.14815 0.11 1.825 -0.060274 Right glider 0 0 0 0.11 1.6167 0.06804 Momentum and Energy Calculations a) Calculate the momentum of each glider before and after collision (the left glider's momentum after collision should be negative!) the total momentum before and after collision the change AP = (PAfter - PBefore) in each momentum calculated above the percentage change [AP/(PBefore)]x100 in each momentum calculated above Enter the results in the table below. Use kilograms for mass and m/s for velocities. Enter the momentum values using five significant digits. Round off the percentages to two significant digits.Elastic Collision KE Before KE After Change (AKE) % Change KE Calculations Left glider 0.0032922 0.00054494 -0.0027472 -143 Right glider O 0.0020832 0.0020832 200 Total Kinetic Energy 0.0032922 0.00262821. Has the momentum of the left glider changed significantly during the collision? What force was responsible for the change? What exerted that force on the left glider? Explain your answers to get any credit. (5 points) Enter answers here 2. Calculate the force (in Newtons) that changed the momentum of the left glider using F = AP/At, with 4t being the collision time. What was the direction of the force? (5 points) Enter calculations, result, and answer here 3. Has the momentum of the right glider changed significantly during the collision? What force was responsible for the change? What exerted that force on the right glider? Explain your answers to get any credit. (5 points) Enter the answers here 4. Calculate the force (in Newtons) that changed the momentum of the right glider using F = AP/4t, with At being the collision time. What was the direction of the force? (5 points) Enter calculations, result, and answer here5. According to the action and reaction principle, the force felt during the collision by the left glider should equal in magnitude and have opposite direction to the force felt by the right glider. Calculate the percentage difference between the magnitudes of the two forces. Is the action and reaction principle valid during the gliders' collision? Explain your answers to get any credit. (5 points) Enter calculation, answer, and explanation here 6. Did the total momentum of the two-glider system change significantly during the collision? Can you conclude that the total momentum was conserved? If you think that the total momentum was not conserved, what could be the explanation? Are there external forces responsible for the change? Explain your answers to get any credit. (5 points) Enter answers and explanations here 7. Did the total kinetic energy of the two-glider system change significantly during the collision? Can you conclude that the total kinetic energy was conserved? If you think that the total kinetic energy was not conserved, where is the missing energy? Explain your answers to get any credit. (5 points) Enter answers and explanations hereActivity Overview In this activity you will explore the conservation of momentum and the change in kinetic energy during an elastic collision (Part 1), and an inelastic collision (Part II). You will take measurements of velocities before and after collisions. The velocities will then be used to calculate the momentum and kinetic energy of each object, before and after the collision. You will then discuss how the total momentum and kinetic energy of the system changes during the collisions. Theoretical Background Momentum and Forces The linear momentum of a particle is defined as p = my, where m is the mass of the particle and u is its velocity vector. Newton's 2"d Law ca be expressed as EF = = (for constant forces). The change in momentum caused by a constant force F is AP = F . At The total momentum of a system of several particles is the vector sum of all particle momenta. Conservation of Momentum The momentum of a particle does not change when the net force on it is zero. The total momentum of a system conserves if the system is isolated, or if the sum of all external forces is zero. A change in the total momentum is caused only by external forces. Internal forces do not change the total momentum of a system, they only transfer momentum within the system. Momentum during collisions Collisions usually happen very fast, and the effect of external forces can be neglected during the interaction. Thus, to a very good approximation, the colliding objects form an isolated system during the collision, This means that the total momentum of the system conserves during a collision: . the total momentum just before the interaction starts equals the total momentum just after the interaction ends.Although individual momenta may change significantly during the collision due to strong internal impact forces, the total momentumn does not change. Elastic vs. inelastic collisions: During an elastic collision, there is no significant change in the total kinetic energy. After the collision, the objects always separate, recover their initial shape and there is no change in their internal structure. The total kinetic energy just before the collision starts equals the total kinetic energy just after the collision ends. Inelastic collisions show a loss (or gain in the case of explosions) in the total kinetic energy. The objects either stick together or separate with permanent changes in their internal structure. When the objects stick together, the loss in kinetic energy is maximal and the collision is called completely (or totally) inelastic, Experiments, Measurements, Calculations and Analysis Go to Pivot Interactives and open the assignment Collisions which contains two parts. Part I shows two gliders on an air-track colliding elastically; Part II shows a blow-dart being shot at a cart as an example of a completely inclastic collision. In each video you can access rulers and timers to help you determine the velocities before and after collisions. Part I: An Elastic Collision (100 points) Measurements and calculations (65 points) Access Port / and use the CHANGE button to select the collision listed as: Collision Type: Right Stationary (the right glider is at rest before collision) Glider Masses (L-R): 150 g - 450 g (left glider has 150 g and right glider has 450 g) Click on LOAD and play the video to familiarize with the sequence of events. You should see the left glider moving towards the stationary right glider, then a short time collision while the hoops push against each other, and finally the gliders separate and move away from each other.Next, you will use the rulers and the timer to determine the velocities of the gliders before and after collision. Since the gliders move along a frictionless horizontal track, they have constant velocities before and after collision. This means that you can determine each velocity simply by measuring o distance and time and using velocity = distance/time. You will also measure the collision time. Velocity measurements before collision Since before the collision the right glider is at rest, you need to determine only the left glider's velocity. This is how you do it: a) Run the video frame by frame to the instant just before the gliders make contact. Set one ruler with the zero at the front edge of the left glider, as shown in the screen shot below. Notice the thin gop between the hoops, which shows the gilders at the instant just before the collision starts. eeoO 15 Pivot Curp b] Run the video bock to the instant when the front edge of the left glider is 10 cm away from the previous position. Bring the timer on the screen and set it to zero. Your screen should look now like this