2014 Physics Final Exam Format

Transcription

1 2014 Physics Final Exam Format *The review packet is NOT graded. It is provided for your benefit. **Unused hall passes and textbooks will be collected on Friday, June 13. They will NOT be accepted any other day. Remember to bring them to class. Each unused hall pass counts for 1 extra credit point on the final exam. Chapters Covered: Chapter 5: Work & Energy Chapter 6: Momentum & Collisions Chapter 7: Circular Motion & Gravity Chapter 16: Electrostatics Chapters 17-18: Circuits Format: 65 multiple choice questions-scantron You have 65 minutes to finish your exam. When the bell rings, all exams will be collected. What to Study: 1. Review Packet 2. Old Pretests & Chapter Tests Materials Needed: *Calculator (provided) *Reference Sheet *#2 pencils Final Grade: 40% 3 rd quarter grade 40% 4 th quarter grade 20% Final exam 1

2 Chapter 5: Work & Energy 1. According to the scientific definition of work, pushing on a rock accomplishes no work unless there is. A. an applied force greater than its weight B. a net force greater than zero C. an opposing force D. movement in the same direction as the force 2. Which of the following situations doesn t have any work done? A. A truck pulling a trailer along the road B. A waiter carrying a tray to a table C. A soccer player kicks a ball across the field D. A bodybuilder lifts a barbell above his head 3. The total work done in lifting a typical high school physics textbook a vertical distance of 0.10 meter is approximately. A J B. 15 J C. 1.5 J D. 150 J 4. If you push an object just as far while applying twice the force you do. A. twice as much work. B. four times as much work. C. the same amount of work. 5. In which of the following situations is no net work done? A. a runner walks at a constant speed around a track B. a car decelerates to a stop at a stop light C. a ball accelerates going down a hill D. a waiter carries a tray of food to a table of patrons 6. How much work is done by the force lifting a 0.1 kg hamburger vertically upward at constant velocity 0.3 m from a table. A. 0.03J B. 0.3 J C. 0.1 J D. 0.4 J 7. A pendulum is made from a 7.50-kilogram mass attached to a rope connected to the ceiling of a gymnasium. The mass is pushed to the side until it is at position A, 1.5 meters higher than its equilibrium position. After it is released from rest at position A, the pendulum moves freely back and forth between positions A and B. What is the total amount of kinetic energy that the mass has as it swings freely through its equilibrium position? (Neglect freedom) A. 11 J B. 110 J C. 94 J D. 920 J 2

3 8. What is the common formula for work? Assume that W is the work, F is a constant force, Δv is the change in velocity, and d is the displacement. A. W = FΔv B. W = Fd 2 C. W = Fd D. W = F 2 d 9. Which of the following forms of energy is not involved in dribbling a basketball? A. gravitational potential energy B. kinetic energy C. elastic potential energy D. electromagnetic energy 10. If friction is the only force acting on an object during a given physical process, which of the following assumptions can be made in regard to the object s kinetic energy? A. the kinetic energy decreases B. the kinetic energy increases C. the kinetic energy remains constant D. the kinetic energy decreases and then increases 11. The gravitational potential energy, with respect to Earth, that is possessed by an object is dependent on the object s. A. acceleration B. position C. momentum D. speed 12. A wound spring provides the energy to propel a toy car across a level floor. At time ti,the car is moving at speed vi across the floor and the spring is unwinding, as shown below. At time tf, the spring has fully unwound and the car has coasted to a stop. Which statement best describes the transformation of energy that occurs between times ti and tf? A. Gravitational potential energy at ti is converted to internal energy at tf. B. Elastic potential energy at ti is converted to kinetic energy at tf. C. Both elastic potential energy and kinetic energy at ti are converted to internal energy at tf. D. Both kinetic energy and internal energy at ti are converted to elastic potential energy at tf. 13. Which graph represents the relationship between the gravitational potential energy (GPE) of an object near the surface of Earth and its height above the surface of Earth? 14. Which is an SI unit for work done on an object? A. B. C. D. 3

4 15. If the displacement of a horizontal mass-spring system was halved, the elastic potential energy in the system would change by a factor of. A. ¼ B. ½ C. 2 D If the mass in a horizontal mass-spring system was halved, the elastic potential energy in the system would change by a factor of. A. 0 (no change) B. 2 C. ½ D. ¼ 17. What is the potential energy of a 1.0 kg mass 2.0 m above the ground? A. 1.0 J B. 10 J C. 9.8 J D J 18. A 1000-kg car and a 2000-kg car are hoisted the same distance in a gas station. Raising the more massive car requires. A. less work. B. as much work. C. twice as much work. D. four times as much work. E. more than 4 times as much work. 19. A ball is dropped from the top of a cliff. Which graph best represents the relationship between the ball s total energy and elapsed time as the ball falls to the ground? [Neglect friction.] 20. As a ball falls freely toward the ground, its total mechanical energy. A. decreases B. increases C. remains the same 21. Which statement describes the kinetic energy and total mechanical energy of a block as it is pulled at constant speed up an incline? A. Kinetic energy decreases and total mechanical energy increases. B. Kinetic energy decreases and total mechanical energy remains the same. C. Kinetic energy remains the same and total mechanical energy increases. D. Kinetic energy remains the same and total mechanical energy remains the same. 22. Which of the following refers to the sum of kinetic energy and all forms of potential energy? A. mechanical energy B. non-mechanical energy C. internal energy D. chemical potential energy 23. Which of the following is not a form of mechanical energy? A. electrical energy B. gravitational potential energy C. elastic potential energy D. kinetic energy 24. Friction converts kinetic energy to. A. thermal energy B. potential energy C. chemical energy D. mechanical energy 25. A more powerful motor can do. A. more work in a longer time interval B. the same work in a shorter time interval 4

5 C. less work in a longer time interval D. the same work in a longer time interval Matching: Match the correct definition with the term. Terms may be used once, more than once, or not at all. (1 point each) 26. the product of the component of a force along the direction of displacement and the magnitude of the displacement 27. the energy available for use when a deformed elastic object returns to its original configuration 28. the energy associated with an object because of its position, shape or condition of the object 29. the sum of the kinetic energy and all forms of potential energy 30. the energy of an object that is due to an object s motion 31. the potential energy stored in the gravitational fields of interacting bodies 32. a quantity that measures the rate at which work is done or energy is transferred a. Work is b. Kinetic energy is c. Gravitational potential energy is d. Elastic potential energy is e. Power is f. Mechanical energy is g. Potential energy is h. Thermal energy is i. Force is Matching. Matching: Match the term with its correct measurement.. Terms may be used once, more than once, or not at all. (1 point each) 33. The base unit for energy is The base unit for mass is The base unit for work is. 36. The base unit for force is. 37. The base unit for the force of gravity is The base unit for power is. 39. The base unit for velocity is The base unit for time interval is. a. s b. W c. J d. m e. m/s 2 f. kg g. N h. m/s 5

6 41. For each object list the type of energy it possesses. Each type of energy may be used once, more than once, or not at all. Electrical, electromagnetic, chemical, elastic potential, gravitational potential, kinetic, thermal, nuclear a. lamp: b. bungee cord: c. spinning wheel: d. sky diver in a plane: e. water behind a dam: f. wood: 42. For each of the following energy transformations, name a device that transforms the first type of energy into the second. Include a description explaining how the energy is converted. Your description must be clear to receive all points. a. kinetic - thermal: b. electrical kinetic: 43. For each of the labeled locations of the roller coaster state what is happening to the gravitational potential energy and kinetic energy as the car begins from rest at Point a. Point c is on the ground. Use the following descriptions: increasing, decreasing, maximum, zero to fill in the chart. (6 points) Point a PE KE Point b Point c 44. A scale contains a spring. Placing a mass on the scale causes the spring to be compressed by 15 cm and creates 3.50 J of elastic energy. Calculate the spring constant of the spring. (3 points) 45. A worker pushes a box with a horizontal force of 74 N over a level distance of 7.0 m. A frictional force of 30 N acts on the box in a direction opposite to that of the worker. Calculate the net work done on the box? (3 points) 6

7 46. How much power will Dylan use doing pushups if he has a mass of 90 kg and raises himself 0.19 m each time? Each pushup takes Dylan 2.1 s to do. (3 points) 47. Explain how Dylan can decrease his power. (2 points) 48. In the sport of bungee jumping people stand on a high platform and allow themselves to fall while tied to the platform by an elastic cord attached to their ankles. Johanna does a bungee jump. The un-stretched length of the bungee cord is 20.0 m. Johanna s mass is 54 kg. In her initial drop the lowest point she reaches is when her feet are 45 m below the platform. (8 points) a. What is the total energy of Johanna at Point #A? b. What is the total energy of Johanna at Point #B? c. Friction causes Johanna to lose energy to heat. If Johanna loses 25% of her total energy in the first bounce, what is the maximum height above the ground that Johanna can rebound to? 7

8 d. If Johanna didn t have a bungee cord attached to her ankles, what velocity would she be going at point B? 8