1. A baseball is thrown at an angle of 40.0 above the horizontal. The horizontal component of the baseball s initial velocity is 12.0 meters per second. What is the magnitude of the ball s initial velocity? A) 7.71 m/s B) 9.20 m/s C) 15.7 m/s D) 18.7 m/s 2. 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 3. Two spheres, A and B, are simultaneously projected horizontally from the top of a tower. Sphere A has a horizontal speed of 40. meters per second and sphere B has a horizontal speed of 20. meters per second. Which statement best describes the time required for the spheres to reach the ground and the horizontal distance they travel? [Neglect friction and assume the ground is level.] A) Both spheres hit the ground at the same time and at the same distance from the base of the tower. B) Both spheres hit the ground at the same time, but sphere A lands twice as far as sphere B from the base of the tower. C) Both spheres hit the ground at the same time, but sphere B lands twice as far as sphere A from the base of the tower. D) Sphere A hits the ground before sphere B, and sphere A lands twice as far as sphere B from the base of the tower 4. A plane flying horizontally above Earth s surface at 100. meters per second drops a crate. The crate strikes the ground 30.0 seconds later. What is the magnitude of the horizontal component of the crate s velocity just before it strikes the ground? [Neglect friction.] A) 0 m/s B) 100. m/s C) 294 m/s D) 394 m/s
5. The diagram below shows a student throwing a baseball horizontally at 25 meters per second from a cliff 45 meters above the level ground. 7. In the diagram below, a stationary observer on the ground watches as a seagull flying horizontally to the right drops a clamshell. Approximately how far from the base of the cliff does the ball hit the ground? [Neglect air resistance.] A) 45 m B) 75 m C) 140 m D) 230 m 6. A baseball player throws a ball horizontally. Which statement best describes the ball's motion after it is thrown? [Neglect the effect of friction.] A) Its vertical speed remains the same, and its horizontal speed increases. B) Its vertical speed remains the same, and its horizontal speed remains the same. C) Its vertical speed increases, and its horizontal speed increases. D) Its vertical speed increases, and its horizontal speed remains the same. Which diagram best represents the path of the falling clamshell as seen by the observer? [Neglect air resistance.] A) B) C) D)
8. The diagram below shows the muzzle of a cannon located 50. meters above the ground. When the cannon is fired, a ball leaves the muzzle with an initial horizontal speed of 250. meters per second. [Neglect air resistance.] Which action would most likely increase the time of flight of a ball fired by the cannon? A) pointing the muzzle of the cannon toward the ground B) moving the cannon closer to the edge of the cliff C) positioning the cannon higher above the ground D) giving the ball a greater initial horizontal velocity 9. Base your answer to the following question on the information and diagram below. A student standing on a knoll throws a snowball horizontally 4.5 meters above the level ground toward a smokestack 15 meters away. The snowball hits the smokestack 0.65 second after being released. [Neglect air resistance.] At the instant the snowball is released, the horizontal component of its velocity is approximately A) 6.9 m/s B) 9.8 m/s C) 17 m/s D) 23 m/s
10. The diagram represents a bicycle and rider traveling to the right at a constant speed. A ball is dropped from the hand of the cyclist. 11. Which graph best represents the relationship between the velocity of an object thrown straight upward from Earth s surface and the time that elapses while it is in the air? [Neglect friction.] A) Which set of graphs best represents the horizontal motion of the ball relative to the ground? [Neglect air resistance.] A) B) B) C) C) D) D) 12. A 0.25-kilogram baseball is thrown upward with a speed of 30. meters per second. Neglecting friction, the maximum height reached by the baseball is approximately A) 15 m B) 46 m C) 74 m D) 92 m 13. A 0.2-kilogram red ball is thrown horizontally at a speed of 4 meters per second from a height of 3 meters. A 0.4-kilogram green ball is thrown horizontally from the same height at a speed of 8 meters per second. Compared to the time it takes the red ball to reach the ground, the time it takes the green ball to reach the ground is A) one-half as great B) twice as great C) the same D) four times as great
14. Base your answer to the following question on the information and diagram below. A child kicks a ball with an initial velocity of 8.5 meters per second at an angle of 35 with the horizontal, as shown. The ball has an initial vertical velocity of 4.9 meters per second and a total time of flight of 1.0 second. [Neglect air resistance.] 16. What is the approximate total time required for the ball to reach the ground? [Neglect air resistance.] A) 12.2 s B) 2.04 s C) 3.00 s D) 3.50 s The maximum height reached by the ball is approximately A) 1.2 m B) 2.5 m C) 4.9 m D) 8.5 m Base your answers to questions 15 and 16 on the information and diagram below. A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 meters high. 15. What is the horizontal velocity of the ball just before it reaches the ground? [Neglect air resistance.] A) 9.81 m/s B) 20.0 m/s C) 34.3 m/s D) 68.6 m/s
17. A ball is projected horizontally to the right from a height of 50. meters, as shown in the diagram below. A) B) Which diagram best represents the position of the ball at 1.0-second intervals? [Neglect air resistance.] C) D)
18. Base your answer to the following question on the following information. In the diagram below, a 10.-kilogram sphere, A, is projected horizontally with a velocity of 30. meters per second due east from a height of 20. meters above level ground. At the same instant, a 20.-kilogram sphere, B, is projected horizontally with a velocity of 10. meters per second due west from a height of 80. meters above level ground. [Neglect air friction.] Compared to the vertical acceleration of sphere A, the vertical acceleration of sphere B is A) the same B) twice as great C) one-half as great D) four times as great 19. A 2-kilogram block is dropped from the roof of a tall building at the same time a 6-kilogram ball is thrown horizontally from the same height. Which statement best describes the motion of the block and the motion of the ball? [Neglect air resistance.] A) The 2-kg block hits the ground first because it has no horizontal velocity. B) The 6-kg ball hits the ground first because it has more mass. C) The 6-kg ball hits the ground first because it is round. D) The block and the ball hit the ground at the same time because they have the same vertical acceleration. 20. A red ball and a green ball are simultaneously thrown horizontally from the same height. The red ball has an initial speed of 40. meters per second and the green ball has an initial speed of 20. meters per second. Compared to the time it takes the red ball to reach the ground, the time it takes the green ball to reach the ground will be A) the same B) twice as much C) half as much D) four times as much 21. Base your answer to the following question on the information below. An outfielder throws a baseball to the first baseman at a speed of 19.6 meters per second and an angle of 30. above the horizontal. Which pair represents the initial horizontal velocity ( vx) and initial vertical velocity (vy) of the baseball? A) vx = 17.0 m/s, vy = 9.80 m/s B) vx = 9.80 m/s, vy = 17.0 m/s C) vx = 19.4 m/s, vy = 5.90 m/s D) vx = 19.6 m/s, vy = 19.6 m/s
22. Base your answer to the following question on the information and diagram below A golf ball leaves a golf club with an initial velocity of 40.0 meters per second at an angle of 40º with the horizontal. 23. Base your answer to the following question on the information and diagram below. A projectile is launched at an angle of 60.º above the horizontal at an initial speed of 40. meters per second, as shown in the diagram below. The projectile reaches its highest altitude at point P and strikes a target at point T. [Neglect air resistance.] What is the total horizontal distance traveled by the golf ball during the first 2.50 seconds of its flight? A) 100. m B) 76.6 m C) 64.3 m D) 40.0 m Which graph best represents the horizontal speed of the projectile as a function of time? [Neglect air resistance.] A) B) C) D)
24. Base your answer to the following question on the diagram below which represents a ball being kicked by a foot and rising at an angle of 30.º from the horizontal. The ball has an initial velocity of 5.0 meters per second. [Neglect friction.] What is the magnitude of the horizontal component of the ball's initial velocity? A) 2.5 m/s B) 4.3 m/s C) 5.0 m/s D) 8.7 m/s 25. A projectile is launched at an angle above the ground. The horizontal component of the projectile's velocity. vx, is initially 40. meters per second. The vertical component of the projectile's velocity, vy, is initially 30. meters per second. What are the components of the projectile's velocity after 2.0 seconds of flight? [Neglect friction.] A) vx = 40. m/s and vy = 10. m/s B) vx = 40. m/s and vy = 30. m/s C) vx = 20. m/s and vy = 10. m/s D) vx = 20. m/s and vy = 30. m/s 26. A soccer ball kicked on a level field has an initial vertical velocity component of 15.0 meters per second. Assuming the ball lands at the same height from which it was kicked, what is the total time the ball is in the air? [Neglect friction.] A) 0.654 s B) 1.53 s C) 3.06 s D) 6.12 27. A golf ball is hit at an angle of 45 above the horizontal. What is the acceleration of the golf ball at the highest point in its trajectory? [Neglect friction.] A) 9.8 m/s 2 upward B) 9.8 m/s 2 downward C) 6.9 m/s 2 horizontal D) 0.0 m/s 2
28. Four identical projectiles are launched with the same initial speed, v, but at various angles above the level ground. Which diagram represents the initial velocity of the projectile that will have the largest total horizontal displacement? [Neglect air resistance.] A) B) C) D) 29. Four projectiles, A, B, C, and D, were launched from, and returned to, level ground. The data table below show the initial horizontal speed, initial vertical speed, and time of flight for each projectile. 32. A projectile is fired from a gun near the surface of Earth. The initial velocity of the projectile has a vertical component of 98 meters per second and a horizontal component of 49 meters per second. How long will it take the projectile to reach the highest point in its path? A) 5.0 s B) 10. s C) 20. s D) 100. s Which projectile traveled the greatest horizontal distance? [Neglect friction.] A) A B) B C) C D) D 30. 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 31. Base your answer to the following question on the information below. A ball is projected vertically upward from the surface of the Earth with an initial speed of +49 meters per second. The ball reaches its maximum height in 5.0 seconds. (Disregard air resistance.) What is the maximum height reached by the ball? A) 24.5 m B) 49.0 m C) 122.5 m D) 245 m
Answer Key HW two-dimensional motion 1. C 2. C 3. B 4. B 5. B 6. D 7. D 8. C 9. D 10. A 11. D 12. B 13. C 14. A 15. B 16. D 17. D 18. A 19. D 20. A 21. A 22. B 23. D 24. B 25. A 26. C 27. B 28. B 29. D 30. B 31. C 32. B