I need help with the last page. Not sure which speed to use to calculate KE and PE. Average speed or final speed. Help!!

Oct 16 Lab Exploration: Momentum Energy is one of the most fundamental parts of our universe. Energy exists in various forms, two of which are discussed in this laboratory exploration. Kinetic energy (KE) is the energy of motion. The kinetic energy of an object is the energy it possesses because of its motion. Given the object mass (m) and speed (v), the kinetic energy (KE) is expressed as KE = 1/2 mv2 Potential energy (PE) is the energy of position. For example, an object may have the capacity for doing work as a result of its position in a gravitational field (gravitational potential energy). It may have elastic potential energy as a result of a stretched spring or other elastic deformation. The most common use of gravitational potential energy is SCI1501 PHYSICAL SCIENCE LAB for an object near the surface of the Earth where the gravitational acceleration can be Lab #3: Momentum assumed to be constant at about g = 9.8m/s2. The gravitational potential energy (PE) of an object of mass (m) at a height (h) above a reference level, is expressed as Prof. Kenny L. Tapp PART I: DATA COLLECTION PE = mgh PART II. DATA ANALYSIS & APPLICATION Watch the Momentum Lecture video to collect data for this Lab Exploration. 1. Mass of the ball: m = 66.8 1. Using the appropriate equations, calculate the Kinetic Energy and Potential 9 = 0.0668 kg Energy for each height at the top of the ramp. Record your values in Table 5.2. Recall that the object starts from rest. 2. Length of track = 50. 8 cm = 0.508 m 2. Calculate the Kinetic Energy and Potential Energy for each height at the bottom 3. Complete Table 5.1 using measured and calculated data. of the ramp. Record your values in Table 5.2. Recall that the height (h) is a. With the stopwatch, measure the time it takes for the ball to reach the end measured from the surface of the Football Field of Science. of the track (at its exit). Record the time value in seconds (s). b. Since the ball (metal bearing) is accelerating smoothly, the speed at the 3. Calculate the Total Energy (KE + PE) for each height at the top and bottom of the bottom of the ramp is twice the average speed. The average speed ramp by adding the appropriate kinetic and potential energies. Record your represents the entire length of the track over time (cm/s). values in Table 5.2 i. Use the length of the track and the time to calculate average speed. ii. We need to calculate the final speed of the ball when it exited the Top of Ramp KE Bottom of Ramp track (reached the end of the track). Use this equation: KE mass . spea PE KE + PE KE PE Final speed = 2 x average speed KE + PE (joules) (joules) (joules) PE = (joules) (joules) c. Repeat these observations and calculations for books 2-4 (joules) 1 book length of track length of height |height average final time average speed speed (s) speed (cm) track (m) (cm) (m) 2 books (cm/s) (m/s) (m/s) 1 book 50.8 0. 508 3 book 2.5 10.025 3.4 14.94 0, 1494 0. 2988 2 books 4 books 50.8 01508 3.4 14.94 0. 1494 10. 2988 Table 5.2: Energy of Metal Ball. 3 books 50.8 0. 508 0.07 3.4 14.94 0 , 1494 0. 2988 PART III: EXPERIMENT CONCLUSIONS 4 books 150,8 0. 508 9 0,09 3 45 14.72 0. 1472 0 . 2944 Table 5.1: Speed of Metal Ball 1. Describe how the kinetic and potential energies vary between the top and the bottom of the ramp (any increase or decrease in the energies). 4. Use this space to show your work for converting units and/or calculating speeds. length of trade 2. Is the energy of the object (metal ball) conserved? Explain. 50.8 , time = average speed 50.8/ 3.4 = 14.94 50. 8/ 3. 45 = 14.72 3. What relationships exist between the height of the ramp and the kinetic/potential energies? How does the gravitational potential energy at the top of the ramp compare cm tom = back to places ( km him dm m dmcg mm ) with the kinetic energy at the bottom of the ramp? final speed = 2x average speed Page 2 of 3 Page 3 of 3 0. 1494 x 2 : 0. 1472 x 2 = 0 .2989 0:2944