Physics Final Review

Physics Final Review 1. The number 10.060 contains how many significant digits? a. 3 c. 5☺ b. 4 d. 6 2. The value of 1275 written correctly as two significant digits would be a. 12 c. 1.2 x 103 b. 13 d. 1.3 x 103☺ 3. The symbol ∆ (delta) means that you must a. multiply two values b. divide one value by another c. subtract to find the difference between two values☺ d. add to find the sum of two values 4. Which of the following quantities is a scalar quantity? a. speed☺ b. velocity c. acceleration d. displacement 5. Which of the following quantities is a vector quantity? a. time interval b. distance c. work d. velocity☺ 6. Which statement correctly describes the relationship between distance and displacement between two specific points? a. Distance is always equal to the magnitude of the displacement. b. Distance is always greater than the magnitude of the displacement. c. Distance is never equal to the magnitude of the displacement. d. Distance is sometimes equal to the magnitude of the displacement☺. 7. Which quantity depends on the path that is taken between two points? a. distance☺ b. displacement c. velocity d. acceleration Use the information below to answer the following question The Galileo spacecraft that reached Jupiter in 1995 sent back a wealth of information about the giant planet. Galileo launched a probe into the atmosphere of Jupiter. Before it was eventually crushed by the immense pressure of Jupiter’s lower atmospheric layers, the probe relayed information back to Earth. Galileo used the gravitational forces between Venus and Earth to accelerate to a speed of 39 km/s Numerical Response 1 The distance Galileo travelled in one minute at a speed of 39 m/s, expressed in scientific notation, is b x 10 w m. The value of b is _______________m.2.34x103 Use the following graph to answer the next two questions 8. From t=1 s until t=2 s, the car is Velocity vs. Time of a Car's Trip stopped accelerating uniformly negatively accelerating uniformly travelling at uniform speed☺ 12 10 Velocity m/s a. b. c. d. 8 6 4 2 0 1 2 Time (s) 9. The distance that the car travelled from t =0 s to 1 s and from t = 1 s to 2s are, respectively, a. b. c. d. 5.0 m and 0 m 5.0 m and 10.0 m☺ 10.0 m and 5.0 m 10.0 m and 10.0 m Numerical Response 2 Wayne Gretzky is arguably the greatest hockey player of all time. He holds many individual including the NHL career record for points scored. If Gretzky shoots the puck at a speed of 90 km/h from the top of the offensive face-off circle 15 m from the net, how long will the puck take to reach the net? _________ s 0.60 (Round and record your answer to two significant digits) Use the following information to answer the next two questions Some of the fastest moving arachnids are the long-legged Sun spiders (genus Solpuga) found in semi-desert areas throughout the world. These spiders are capable of moving up to 16 km/h. 10. Moving at maximum speed, what is the shortest time it would take a Sun Spider to run between two fig trees that are 3.6 m apart? a. b. c. d. 0.23 s 14 s 1.5 s 0.81 s☺ 3 Use the following information to answer the next question. 11. Which velocity-time graph describes the same motion as the displacement-time graph shown above? A. B. ☺ C. D. v 12. Which statement about a graph of position versus time is not true? a. A horizontal line indicates that the object was standing still. b. A downward slope of a straight line indicates that the object was slowing down☺. c. An upward slope of a straight line indicates that the object was moving at a constant velocity. d. An upward curving line (a changing slope) indicates that the object was accelerating. 13. What force is needed to lift a 4.54 kg bag of sugar at constant speed? a. b. c. d. 4.54 N 44.5 N☺ 0.463 N The force cannot be calculated unless you know the distance the sugar is lifted. 14. The weight of an object is a. b. c. d. the same as its mass the force of gravity acting on its mass☺ not related to its mass any force acting on its mass Numerical Response 3 Imagine that you carry a box of books, weighing 67.8 N, up a flight of stairs. If each step is 15.0 cm high, and there are 22.0 steps in the flight of stairs, how much work do you do on the box of books? ______________________ J224 (Round and record your answer to three significant digits) 15. According to the formula for kinetic energy, what combination of units is the same as a joule? [Hint: consider what you use to calculate potential energy] A C. B☺. D. 16. When you throw a ball into the air and it reaches its maximum height a. b. c. d. the ball would contain only kinetic energy the ball would contain half potential and half kinetic energy the ball would be moving at it maximum velocity the ball would contain all potential energy☺ 17. A soccer goalie catches and holds the fast-moving ball. What happens to the kinetic energy of the ball? a. b. c. d. Kinetic energy stays the same because energy is conserved. Kinetic energy is destroyed because the ball stops moving. Kinetic energy is transformed into potential energy. ☺ Kinetic energy is transformed into heat. 18. How can you increase the kinetic energy of a person moving on a playground swing? a. b. c. d. Push in the same direction as the swing is moving. ☺ Push in the direction opposite to the motion of the swing. Push sideways to change the direction the swing is moving. Kinetic energy cannot be increased because energy is conserved. Use the following information to answer the next three questions Pierre Lueders from Edmonton, Alberta, is a world and Olympic champion in the twoman bobsled event. Lueders trains at one of the world’s most challenging runs located in Calgary Alberta. The bobsled run at the Calgary Olympic Park has a length of 1500 m and a height of 121 m. 19. A bobsled including its riders, has a mass of 250 kg, how much potential energy doe the bobsled have as it is about to start its run? a. 297 MJ☺ b. 297 kJ c. 29.7 MJ d. 297 J 20. If all the potential energy from the bobsled is converted into kinetic energy as the bobsled speeds past the finish line, what is the bobsled’s velocity? a. 2374.0 m/s b. 97.4 m/s c. 48.7 m/s☺ d. 1187.0 m/s 21. Although this potential energy is converted into kinetic energy, some potential energy is a. b. c. d. Evaporated into the atmosphere Converted to mass Conserved as potential energy Lost through friction☺ 22. A race car races a 100 m sprint track at an average speed of 9.50 m/s. If the car's kinetic energy is 9.40 x 103J what is its mass? a. b. c. d. 1.98 x 103 m/s 208 kg☺ 104 kg 52.1 kg 23. Which statement about the relationship between work and kinetic energy is not true? a. b. c. d. When a force does work on an object, the object might gain kinetic energy. When a force does work on an object, the object might lose kinetic energy. When a force does work on an object, the object always gains kinetic energy. ☺ When a force does work on an object, the object might have no change in its kinetic energy. 24. Which statement about the motion of a pendulum is not true? a. b. c. d. All the energy is gravitational potential energy at the top of the swing. All the energy is gravitational potential energy at the bottom of the swing. ☺ All the energy is kinetic energy at the bottom of the swing. The energy is partly gravitational potential energy and partly kinetic energy between the top and bottom of the swing. 25. The useful output energy of a motor is a. b. c. d. sound heat light kinetic energy☺ Use the following information to answer the next 2 questions. Electric motors are between 50% and 90% efficient at converting electrical energy to useful energy, which causes the motion of the motor shaft. Suppose that a particular motor is measured to be 73% efficient. 26. The motor described above is 73% efficient. What does this mean? a. b. c. d. 73% of the input energy is wasted. 73% of the input energy is converted to heat. 73% of the input energy is converted to kinetic energy. ☺ 73% of the input energy is not converted to some other form. 27. For every 100 J of input energy supplied to the motor, how much energy is wasted? a. 27 J☺ b. 46 J c. 73 J d. 100 J Use the following information to answer the next question. The process of photosynthesis allows green plants to produce glucose, C6H12O6. Glucose is used as a food source. The chemical equation for photosynthesis is: 6CO2(g) + 6H2O(l)  C6H12O6(aq) + 6O2(g) 28. The process of photosynthesis results in an increase in a. b. c. d. kinetic energy potential energy☺ light energy thermal energy Numerical Response 4 Approximately 4.2 X 104 kJ of energy from sunlight strikes the leaves of a plant in one day. Of this energy 4 200 kJ is converted into useful energy by the plant. The efficiency of photosynthesis in this plant is _____ % 10 (Round and record your answer correct to two significant digits) Part II Matching: Match each of the following descriptions to the correct quantity. You may use each answer once, more than once, or not at all. 18. ____ any form of stored energy M A. Acceleration 19. ____ change in velocity during a unit time interval A B. Chemical potential energy 20. ____ describes size and direction P C. Conservation 21. ____ describes size but not direction N D. Displacement 22. ____ difference between two times I E. Distance 23. ____ displacement in a unit time (for example, one second F. Elastic potential energy or one hour) Q 24. ____ distance traveled in a unit time (for example, one G. Force H. Gravitational potential second or one hour) O energy 25. ____ energy stored in a material that is bent, compressed, I. Interval or stretched and will return to its original shape when J. Magnitude released. F K. Nuclear potential energy 26. ____ energy stored in the bonds which hold atoms, ions, and molecules together B L. Position M. Potential energy 27. ____ energy stored in the inner core of an atom K N. Scalar 28. ____ length of a path from one point to another E O. Speed 29. ____ location relative to a particular reference point L P. Vector 30. ____ size or amount J Q. Velocity 31. ____ stored energy associated with the force of gravity R. Work between two objects H 32. ____ straight line distance and direction from one point to another D Part III Long Answer: A jackrabbit can reach a velocity of +18.5 m/s from a resting position in 1.25 s. What is the rabbit’s acceleration? 14.8 m/s While riding up a chair lift, a 54.8 kg skier gains 4.22  105 J of gravitational potential energy. The top of the ski lift is what vertical distance above its base? 785m In a toy, a 92.4 g ball rolls into a spring and compresses the spring. If the ball is rolling at 4.28 m/s when it collides with the spring and, at maximum compression, the spring is storing 0.560 J of elastic potential energy, with what efficiency is the ball’s kinetic energy converted into elastic potential energy of the spring? 66.2% Fill in the following chart, the first example is done for you: Graph Sketch Distance vs. Time (uniform motion) d Calculations obtained from graph Slope of graph = velocity t Distance vs. Time (at rest) Slope of graph = velocity Slope = 0 Velocity vs. Time (uniform velocity) Area under graph = distance A=bh Velocity vs. Time (positive acceleration) Area under graph = distance A=1/2bh Answer Key: 1. C 2. D 3. C 4. A 5. D 6. D 7. A 8. D 9. B 10. D 11. B 12. B 13. B 14. B 15. B 16. D 17. C 18. A 19. A 20. C 21. D 22. B 23. C 24. B 25. D 26. C 27. A 28. B NR1: 2.34 NR2: 0.60 NR3: 224 NR4: 10 Graph Sketch Distance vs. Time (uniform motion) d PARTII: 18. M 19. A 20. P 21. N 22. I 23. Q 24. O 25. F 26. B 27. K 28. E 29. L 30. J 31. H 32. D PART III: 1. 14.8 m/s2 2. 785 m 3. 66.2% Calculations obtained from graph Slope of graph = velocity t Distance vs. Time (at rest) Slope of graph = velocity Slope = 0 d t Velocity vs. Time (uniform velocity) Area under graph = distance A=bh v t Velocity vs. Time (positive acceleration) Area under graph = distance A=1/2bh v t