AP Physics Circular Motion Practice Test B,B,B,A,D,D,C,B,D,B,E,E,E, 14. 6.6m/s, 0.4 N, 1.5 m, 6.3m/s, 15. 12.9 m/s, 22.9 m/s Answer the multiple choice questions (2 Points Each) on this sheet with capital letters in the space provided. Answer the other problems in the space provided. Show all of your work and box in your answers. Use g=9.8 m/s 2 and the radius of the Earth = 6.37 10 6 m. 1. An object moving on a plane circular path with constant speed has A. zero acceleration. B. a constantly changing velocity. C. a tangential acceleration. D. an outward radial acceleration. E. a changing acceleration magnitude. 2. A bicycle tire of radius 0.4 m rotates 600 times in 800 s. The average tangential speed of the valve stem is A. 2.6 m/s. B. 1.9 m/s. C. 0.9 m/s. D. 4.2 m/s. E. 3.4 m/s. 3. The angular distance that the valve stem covers in the above problem is A. 623 rad. B. 3770 rad. C. 1885 rad. D. 2513 rad. E. 5027 rad. 4. A 2.5 kg ball swings in a horizontal circular path at the end of a string. The radius of the circle is 0.6 m and the tension in the string is 32N. The ball's tangential speed is A. 2.8 m/s. B. 3.7 m/s. C. 7.7 m/s. D. 4.4 m/s. E. 9.2 m/s. 5. A space station is in the form of a rotating wheel with a radius of 500 m. The acceleration at the rim equals 2 times the acceleration of gravity at the surface of the Earth. Which of the following is nearest to the angular velocity in RPMs (revs/min)? A. 2.26 RPMs. B. 0.20 RPMs. C. 0.70 RPMs D. 1.9 RPMs. E. 0.37 RPMs. 1
6.A car travels around an unbanked (horizontal) highway curve of radius 50 m. The coefficient of static friction is 0.6. The maximum speed that the car can travel without skidding is A. 22.1 m/s. B. 23.4 m/s. C. 26.5 m/s. D. 17.1 m/s. E. not enough information given. 7. A 2.5 kg tribble is placed in a bucket and whirled in a 1.4 m radius vertical circle at a constant tangential speed. If the force on the tribble from the bucket does not exceed 10 times its weight (tribbles are a hardy species), the maximum tangential speed is A. 15.4 m/s. B. 12.3 m/s. C. 11.1 m/s. D. 11.7 m/s. E. 123.5 m/s. 8. A Ferris Wheel with a radius of 25 m is taken over by Dennis Hopper. What is the tangential speed Dennis needs to make the ride exceed so that people will fly off at the top? (assume they don't hold on, no seatbelts, and neglect friction) A. 5.3 m/s. B. 15.7 m/s. C. 14 m/s. D. 9.8 m/s. E. depends on the mass of the people. 9. A 5.0 kg Foucalt Pendulum swings at the end of a 4.0 m long cable. The pendulum is released from a height of 1.5 m above the lowest position of its swing. What is the maximum tension in the cable? A. 5.4 N. B. 37.0 N. C. 22.0 N. D. 86.0 N. E. 49.0 N. 10. A 1.5 kg tether ball is hit so that it circles the pole with an angular speed of 4 rad/s. The length of the tether is 2.5 m. The angle measured from the tether to the vertical pole is A. 42.0 o B. 75.8 o. C. 80.7 o. D. 61.4 o. E. 57.0 o. 11. The tension in the tether in the above problem is A. 21.6 N. B. 40.0 N. C. 19.0 N. D. 15.2 N. E. 60.0 N. 2
12. A clay ball is travelling in a horizontal circle at the end of a string as shown below. If string is cut at point X, which arrow shows the direction the clay ball will go? A. B. C. D. E. X 13. How many hours would it take the Earth to rotate if a person standing on a bathroom scale on the equator saw the scale read 1/3 her actual weight? The Earth's radius is 6,378,140 m. A. 2.4 hours. B. 2.1 hours. C. 1.9 hours. D. 3.3 hours. E. 1.7 hours. 3
14. (10 Points) A Hot Wheels TM car is released from rest at point A on the frictionless track shown in the diagram below. The mass of the car is 80g. A 2.2m C r = 0.8m D 40 o 1.0m (a) Determine the speed of the car at point B (the bottom of the loop) B (b) Determine the force of the track on the car at point C (the top of the loop) (c) The car continues onto the ramp at point D and flies into the air. Determine its maximum height. (d) The car is released again from a point below point A. Determine the minimum speed required at point B so that the car just makes it through the loop without leaving the track. 4
15. (10 Points) A highway curve that has a radius of curvature of 80 meters is banked at an angle of 12 o as shown below... 12 o (a) Determine the maximum speed that the car can travel so that no slipping occurs if there is no friction present. (b) The coefficient of friction between the road and the car is 0.4 On the diagram below, in which the block represents the car, draw and label all of the forces present. (c) Determine the maximum speed that the car can travel so that no slipping occurs now that there is friction present. 5