<p>Name ______period ______2nd 9 weeks physics test review Due Monday 12/ 14/ 2015</p><p>USE THE FOLLOWING DIAGRAM FOR THE NEXT THREE QUESTIONS.</p><p>A ball is kicked at a 50o angle. The initial horizontal velocity is 10m/s and the initial vertical velocity is 15m/s. 1. What is the magnitude of acceleration at each point: A, B, and C?</p><p>2. What is the horizontal velocity at each point? </p><p>3. At which point (A, B, or C) will the football have the smallest vertical velocity? Why?</p><p>4. Explain how decreasing the radius of the loop of a roller coaster increases the acceleration of the riders. 5. Use the picture below to answer the questions. </p><p> a. Using the height formula: how long will it take for the ball to hit the ground?</p><p> b. Using the formula x=voxt, what is the velocity of the launch?</p><p>6. On the picture below, label the centripetal acceleration, the radius, and the tangential velocity. 7. Look at the question below to answer the problem.</p><p> a. If the three rocks above, A, B, and C, were all thrown off a cliff at the same time, which would hit the ground first and why?</p><p>8. If two masses, 5kg and 10 kg respectively, have a force between them of 0.005N, what 2 is the greatest distance between them? ( hint: find r using F= Gm1m2/r )</p><p>9. A comet is heading towards Earth. If the original distance is cut in half, and the mass of the comet is reduced to 1/3 its original mass, what is the new force between the comet and the earth? (hint: see nots on using F to find F’) 10. Which is the action force, and which is the reaction force: a. ______The gravitational pull attracting the comet to the Earth b. ______The gravitational pull of the comet pulling the Earth towards the comet. </p><p>11. A student uses 15N of force to push a box 5m in 20seconds. a. What is the magnitude of work done on the box? (hint: W=Fd)</p><p> b. What is the student’s power output? (hint: P=W/t)</p><p>12. Identify each as either an example of kinetic energy transformed to potential energy (KE to PE) OR potential energy transformed to kinetic energy (PE to KE) a. ______A ball released from a catapult b. ______A ball rolling up a hill</p><p> c. ______Bending a paper clip</p><p> d. ______Coasting down a hill on a bicycle e. ______Starting an automobile engine f. ______Jumping out an airplane g. ______Driving towards a stop sign 13. True or false: the greater the force exerted by a student on a bike over a set distance, the greater the change in kinetic energy. Explain why. </p><p>14. Why doesn’t velocity contribute to the potential energy of an object?</p><p>15. It takes 500J of work to stop a 1000kg moving car. What was the initial velocity </p><p> of the car? (hint: W= KEf - KEi)</p><p>16. It takes 200J of work to get a car initially at rest to move. What was the final </p><p> speed of the car? (hint: W= KEf - KEi) 17. I come to class saying I have created a new energy that will help save the world. Do you believe me? Why or why not?</p><p>18. What is the potential energy of a 10kg weight suspended 10m above the ground? (hint: GPE= mgh)</p><p>19. Look at the table below to answer the questions. Runner Distance Time of travel traveled #1 100m 40s #2 150m 20s #3 200m 15s a. Which runner was the most powerful? Why? 20. Use the picture below to answer the problem. (hint: you can have more than one answer; ME= GPE + KE) </p><p> a. ______Where do you have the greatest Mechanical Energy?</p><p> b. ______Where do you have the greatest GPE?</p><p> c. ______Where do you have the greatest KE?</p><p> d. ______Where will you have the greatest velocity?</p><p>21. Katniss uses 150, 000J of Kinetic energy to pull the bow back 0.70meters. How much elastic energy has she stored in the bow? (hint: EPE=1/2 kx2)</p>