St. Mary's H.S. Physics. Midterm Review

Transcription

1 Name Midterm Review St. Mary's H.S. Physics 1. If a car accelerates uniformly from rest to 15 meters per second over a distance of 100. meters, the magnitude of the car s acceleration is A) 0.15 m/s 2 B) 1.1 m/s 2 C) 2.3 m/s 2 D) 6.7 m/s 2 2. In a race, a runner traveled 12 meters in 4.0 seconds as she accelerated uniformly from rest. The magnitude of the acceleration of the runner was A) 0.25 m/s 2 B) 1.5 m/s 2 C) 3.0 m/s 2 D) 48 m/s 2 3. A child riding a bicycle at 15 meters per second accelerates at -3.0 meters per second 2 for 4.0 seconds. What is the child s speed at the end of this 4.0-second interval? A) 12 m/s B) 27 m/s C) 3.0 m/s D) 7.0 m/s 4. A baseball dropped from the roof of a tall building takes 3.1 seconds to hit the ground. How tall is the building? [Neglect friction.] A) 15 m B) 47 m C) 30. m D) 94 m 5. A 25-newton weight falls freely from rest from the roof of a building. What is the total distance the weight falls in the first 1.0 second? A) 4.9 m B) 2.5 m C) 19.6 m D) 9.8 m 6. A cart travels with a constant nonzero acceleration along a straight line. Which graph best represents the relationship between the distance the cart travels and time of travel?

2 7. The graph below represents the displacement of an object moving in a straight line as a function of time. 9. Base your answer to the following question on the graph below, which represents the motion of a car during a 6.0-second time interval. What was the total distance traveled by the object during the 10.0-second time interval? A) 24 m B) 16 m C) 0 m D) 8 m 8. The graph below shows the relationship between the speed and elapsed time for an object falling freely from rest near the surface of a planet. What is the total distance the object falls during the first 3.0 seconds? A) 12 m B) 24 m C) 44 m D) 72 m What is the acceleration of the car at t = 5.0 seconds? A) 0.0 m/s 2 B) 2.0 m/s 2 C) 2.5 m/s 2 D) 10. m/s Cart A has a mass of 2 kilograms and a speed of 3 meters per second. Cart B has a mass of 3 kilograms and a speed of 2 meters per second. Compared to the inertia and magnitude of of cart A, cart B has A) greater inertia and a smaller magnitude of B) the same inertia and a smaller magnitude of C) the same inertia and the same magnitude of D) greater inertia and the same magnitude of 11. A 5.00-kilogram block slides along a horizontal, frictionless surface at 10.0 meters per second for 4.00 seconds. The magnitude of the block's is A) 50.0 kg m/s B) 20.0 kg m/s C) 200. kg m/s D) 12.5 kg m/s 12. A 75-kilogram hockey player is skating across the ice at a speed of 6.0 meters per second. What is the magnitude of the average force required to stop the player in 0.65 second? A) 120 N B) 290 N C) 690 N D) 920 N

3 13. A 3.1 kilogram gun initially at rest is free to move. When a kilogram bullet leaves the gun with a speed of 500. meters per second, what is the speed of the gun? A) 2.4 m/s B) 500. m/s C) 0.0 m/s D) 7.5 m/s 14. When a 1.0-kilogram cart moving with a speed of 0.50 meter per second on a horizontal surface collides with a second 1.0-kilogram cart initially at rest, the carts lock together. What is the speed of the combined carts after the collision? [Neglect friction.] A) 1.0 m/s B) 0.50 m/s C) 0.25 m/s D) 0 m/s 15. Which object has the greatest inertia? A) a kg bullet traveling at 90. m/s B) a 30.-kg child traveling at 10. m/s on her bike C) a 490-kg elephant walking with a speed of 1.0 m/s D) a 1500-kg car at rest in a parking lot 16. Which situation describes an object that has no unbalanced force acting on it? A) a laboratory cart moving down a frictionless 30. incline B) a hockey puck moving at constant velocity across ice C) an apple in free fall D) a satellite orbiting Earth 17. Which graph best represents the motion of an object in equilibrium?

4 18. Two forces, F1 and F2, are applied to a block on a frictionless, horizontal surface as shown below. If the magnitude of the block's acceleration is 2.0 meters per second 2, what is the mass of the block? A) 1 kg B) 5 kg C) 6 kg D) 7 kg 19. A student pulls a 60.-newton sled with a force having a magnitude of 20. newtons. What is the magnitude of the force that the sled exerts on the student? A) 80. N B) 40. N C) 60. N D) 20. N 20. Which diagram best represents the gravitational forces, Fg, between a satellite, S, and Earth? 21. Which graph represents the relationship between the magnitude of the gravitational force exerted by Earth on a spacecraft and the distance between the center of the spacecraft and center of Earth? [Assume constant mass for the spacecraft.] A) B) C) D) 22. A distance of 1.0 meter separates the centers of two small charged spheres. The spheres exert gravitational force Fg and electrostatic force Fe on each other. If the distance between the spheres centers is increased to 3.0 meters, the gravitational force and electrostatic force, respectively, may be represented as 23. Two 20.-newton forces act concurrently on an object. What angle between these forces will produce a resultant force with the greatest magnitude? A) 0º B) 45º C) 90.º D) 180.º

5 24. Two forces act concurrently on an object on a horizontal, frictionless surface, as shown in the diagram below. What additional force, when applied to the object, will establish equilibrium? A) 16 N toward the right B) 16 N toward the left C) 4 N toward the right D) 4 N toward the left 25. The diagram below represents two concurrent forces. 26. The vector diagram below represents the horizontal component, FH, and the vertical component, FV, of a 24-newton force acting at 35 above the horizontal. Which vector represents the force that will produce equilibrium with these two forces? A) B) C) D) What are the magnitudes of the horizontal and vertical components? A) FH = 3.5 N and FV = 4.9 N B) FH = 20. N and FV = 14 N C) FH = 4.9 N and FV = 3.5 N D) FH = 14 N and FV = 20. N 27. The speedometer in a car does not measure the car s velocity because velocity is a A) scalar quantity and has a direction associated with it B) vector quantity and does not have a direction associated with it C) scalar quantity and does not have a direction associated with it D) vector quantity and has a direction associated with it 28. If the speed of a moving object is doubled, the kinetic energy of the object is A) unchanged B) halved C) quadrupled D) doubled

6 29. Which graph represents the relationship between the kinetic energy and the speed of a freely falling object? 30. 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, as shown in the diagram below. 31. Note that the question below only has three choices. The diagram below represents the path of a stunt car that is driven off a cliff, neglecting friction. Compared to the horizontal component of the car's velocity at point A, the horizontal component of the car's velocity at point B is A) smaller B) greater C) the same What is the total amount of kinetic energy that the mass has as it swings freely through its equilibrium position? [Neglect friction.] A) 11 J B) 94 J C) 110 J D) 920 J

7 32. A car moves with a constant speed in a clockwise direction around a circular path of radius r, as represented in the diagram above. 33. The diagram below shows an object moving counterclockwise around a horizontal, circular track. When the car is in the position shown, its acceleration is directed toward the A) east B) west C) south D) north Which diagram represents the direction of both the object's velocity and the centripetal force acting on the object when it is in the position shown? 34. A golf ball is given an initial speed of 20. meters per second and returns to level ground. Which launch angle above level ground results in the ball traveling the greatest horizontal distance? [Neglect friction.] A) 60 B) 45 C) 30. D) 15