Study Guide for Physics Final Exam—1st semester Name__________________________ Date___________________________ 3. 1. What is a hypothesis? Give and example of a hypothesis we stated during class this semester. 2. Measure the angle of this vector. The teacher was pacing around the classroom. She started at Point A, moved to Point B, then stopped at point C. What is her displacement from Point A? Point A Point D Point B Point C 4. A student walks 3 km east and then 8 km north. What is her displacement? 5. A hiker travels south along a straight path for 9 km. He then turns west and goes 4 km. What is the hiker’s displacement? 6. Give examples of things that would be considered vector quantities. 7. What units might you use to measure the mass of a car? The mass of a fingernail? The length of a pencil? 8. Convert these numbers to standard form: a) 6.02 x 1023 atoms b) 2.3 x 10 -2 minutes c) 9.8 x 10 4 km 9. Write these numbers in scientific notation: a) 0.0000054 minutes b) 236100000 km c) 0.048 cm 160 10. Distance (km) 140 120 100 80 60 40 20 0 0 1 2 3 4 5 6 Time (hours) What is the velocity of the car shown in the graph above? How long would it take the car to travel 100 km? 11. A rock is thrown over a cliff. Describe the rock’s velocity as it travels toward earth. 12. A feather and a bolt are dropped at the same time in a vacuum. Which one will hit the ground first and why? 13. A rock is thrown over a cliff. How far will it have fallen after 4.5 seconds? How fast will it be going? 14. A rock is thrown straight out from a cliff. Compared to a rock that is dropped straight down from the same height, which one will hit the ground first? Explain your answer! 15. Give three examples of projectile motion. 16. A boy throws a ball off a 4.9 m tower. How fast did he throw it if it landed 20 meters away? 17. What angle should a cannon be fired in order to get the maximum distance? 18. Mass X (2 kg) and mass Y (1 kg) are dropped from a tall building at the same time. Which one will be moving faster? Why? 19. Calculate the car’s velocity using the graph at the right. 20. A horse gallops a distance of 15 km in 40 minutes. What is its velocity? 21. A dolphin swims at a speed of 1.85 km/hour. How far has the dolphin traveled after 0.85 hours? 22. A soccer ball is kicked horizontally. What is its average speed if it traveled 25.0 meters after 4.8 seconds? 23. What does the graph tell you about the car’s acceleration? 7 Velocity (m/s) 6 5 4 3 2 1 0 0 5 10 Elapsed time ( sec) 15 24. Draw a ticker-tape diagram of an object that is accelerating. 25. Calculate the car’s acceleration between 2-3 seconds. 26. Suppose a car is moving in a straight line and steadily increases its speed. It moves from 45 km/h to 50 km/h in the first second and from 50 km/h to 55 km/h in the next second. What is the car’s acceleration? 27. A bicyclist accelerates at 0.8 m/s2 during a 5.0 second interval. What is the change in velocity of the bicyclist? 28. Calculate the acceleration of the marble as it rolls down the ramp. 29. Calculate the marble’s velocity at point B. 30. What is inertia? Give examples. 31. A boy drops a ball while riding on a moving train car. Where will the ball fall in relation to the boy? Explain your answer! 32. What causes an object to accelerate? Give an example. 33. An astronaut throws a 1.5 kg rock in outer space. After he throws the rock, how much force is needed to keep the rock in motion? 34. Nellie weighs 200 Newtons. She is hanging on the spring scale in various positions. What should the spring scales read in each situation? 35. How do you determine which object has the greatest inertia? What affects the amount of inertia an object has? 36. Which string has the greatest tension? Why? 37. Give examples of Newton’s 1st law. How does it work in everyday life? 38. If the sun’s gravity suddenly disappeared, explain what would happen to the planets in our solar system. How and where would they move? 39. Using Newton’s Laws, explain why seat belts should always be worn.. 40. The mass of a person that weighs 500 N is about…? 41. How much force is needed to accelerate a 2 kg physics book from rest to a speed of 6 m/s in one second? (a = 6 m/s2) 42. What forces are acting on the ball immediately after it leaves the boy’s hand? 43. Betty has a mass of 85 kg. Betty plans to be the first woman to land on the moon, where the gravitational pull is 1/6 as much as earth’s. What would Betty’s mass be on the moon? 44. A rock weighs 50 N on earth. A second rock weighs 50 N on the moon. How do the masses of these two rocks compare? 45. A student set up a lab as shown on the right. What should she do if she wants to increase the acceleration of the cart? 46. What would the spring scale read in this situation? 47. A tow truck exerts a force of 2850 N on a car, accelerating it at 1.5 m/s 2. What is the mass of the car? 48. How much force would be needed to accelerate a 4.8 kg object to an acceleration of 2.3 m/s2? 49. Sketch a graph showing the relationship between mass and acceleration. 50. Give examples of action/reaction pairs. How do the magnitude of the two forces compare? 51. Draw a free-body force diagram showing the forces acting on a ball that is dropped from a tall building. Label each force. 52. Draw a force diagram showing an object that is accelerating. 53. Fill in the blanks in the force diagram on the right. 54. An unfortunate bug hits the windshield of a moving truck. How does the force of the bug on the windshield compare to the force of the windshield on the bug? Explain ! 55. In the example above, which object would accelerate more? The bug or the windshield? Explain your answer! 56. Give examples of objects that might have a large momentum. What variables affect momentum? 57. A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass, what would its momentum be? 58. A truck and a Volkswagen are traveling at 45 km/ hour and then collide head-on. Which vehicle will experience the greater impact force? Why? 59. The brakes are slammed on a speeding truck and it skids to a stop. If the truck were heavily loaded so it had twice the total mass, what would the skidding distance be? 60. Remember “walking the graph?” Sketch a graph of a person: i. With a velocity of zero ii. Who is accelerating iii. Who is traveling at constant velocity .