2.1 Motion-IBquestions [79 marks] 1. An object is projected vertically upwards at time t = 0. Air resistance is negligible. The object passes the same point above its starting position at times 2 s and 8 s. [1 mark] If g = 10 m s –2, what is the initial speed of the object? 2. A. 50 B. 30 C. 25 D. 4 The distances between successive positions of a moving car, measured at equal time intervals, are shown. [1 mark] The car moves with 3. A. acceleration that increases linearly with time. B. acceleration that increases non-linearly with time. C. constant speed. D. constant acceleration. A boy runs along a straight horizontal track. The graph shows how his speed v varies with time t. After 15 s the boy has run 50 m. What is his instantaneous speed and his average speed when t = 15 s? [1 mark] 4. Two balls X and Y with the same diameter are fired horizontally with the same initial momentum from the same height above the ground. The mass of X is greater than the mass of Y. Air resistance is negligible. [1 mark] What is correct about the horizontal distances travelled by X and Y and the times taken by X and Y to reach the ground? 5. A parachutist of total mass 70 kg is falling vertically through the air at a constant speed of 8 m s –1. [1 mark] What is the total upward force acting on the parachutist? 6. A. 0N B. 70 N C. 560 N D. 700 N A ball starts from rest and moves horizontally. Six positions of the ball are shown at time intervals of 1.0 ms. The horizontal distance [1 mark] between X, the initial position, and Y, the final position, is 0.050 m. What is the average acceleration of the ball between X and Y? 7. A. 2000 m s –2 B. 4000 m s –2 C. 5000 m s –2 D. 8000 m s –2 The variation of the displacement of an object with time is shown on a graph. What does the area under the graph represent? [1 mark] A. No physical quantity B. Velocity C. Acceleration D. Impulse 8. An object is thrown upwards. The graph shows the variation with time t of the velocity v of the object. What is the total displacement at a time of 1.5 s, measured from the point of release? A. 0 m B. 1.25 m C. 2.50 m D. 3.75 m [1 mark] 9. An object is released from a stationary hot air balloon at height h above the ground. [1 mark] An identical object is released at height h above the ground from another balloon that is rising at constant speed. Air resistance is negligible. What does not increase for the object released from the rising balloon? A. The distance through which it falls B. The time taken for it to reach the ground C. The speed with which it reaches the ground D. Its acceleration 10. Two pulses are travelling towards each other. [1 mark] What is a possible pulse shape when the pulses overlap? 11. An object is released from rest in the gravitational field of the Earth. Air resistance is negligible. How far does the object move during [1 mark] the fourth second of its motion? A. B. C. D. 15 m 25 m 35 m 45 m 12. The graph shows the variation of speed v of an object with time t. [1 mark] Which graph shows how the distance s travelled by the object varies with t? 13. A ball is tossed vertically upwards with a speed of 5.0 m s –1. After how many seconds will the ball return to its initial position? [1 mark] A. 0.50 s B. 1.0 s C. 1.5 s D. 2.0 s 14. A projectile is fired horizontally from the top of a cliff. The projectile hits the ground 4 s later at a distance of 2 km from the base of the cliff. What is the height of the cliff? [1 mark] A. 40 m B. 80 m C. 120 m D. 160 m 15. A tennis ball is released from rest at a height h above the ground. At each bounce 50 % of its kinetic energy is lost to its surroundings. What is the height reached by the ball after its second bounce? A. h 8 B. h 4 C. h 2 D. zero [1 mark] 16. The graph shows the variation of the acceleration a of an object with time t. [1 mark] What is the change in speed of the object shown by the graph? A. 0.5 m s–1 B. 2.0 m s–1 C. 36 m s–1 D. 72 m s–1 17. An object of weight W is falling vertically at a constant speed in a fluid. What is the magnitude of the drag force acting on the object? [1 mark] A. 0 W B. 2 C. W D. 2W 18. A student draws a graph to show the variation with time t of the acceleration a of an object. What can the student deduce from this graph only, and what quantity from the graph is used to make this deduction? [1 mark] 19. A mass is suspended from the ceiling of a train carriage by a string. The string makes an angle θ with the vertical when the train is [4 marks] accelerating along a straight horizontal track. What is the acceleration of the train? A. g sin θ B. g cos θ C. g tan θ D. 20. g tan θ An aircraft is moving horizontally. A parachutist leaves the aircraft and a few seconds later opens her parachute. Which graph shows the variation of the vertical speed v with time t for the parachutist from the time she leaves the aircraft until just before landing? [1 mark] 21. An object is at rest at time t = 0. The variation with t of the acceleration a of the object is shown from t = 0 to t = 20 s. [1 mark] What is the speed of the object when t = 15 s? A. 25 m s− 1 B. 50 m s− 1 C. 75 m s− 1 D. 100 m s− 1 22. An object is dropped from rest. Air resistance is not negligible. What is the acceleration of the object at the start of the motion? A. Zero B. Increasing C. Decreasing D. Constant 23. A student throws a stone with velocity v at an angle θ to the vertical from the surface of a lake. Air resistance can be ignored. The acceleration due to gravity is g . What is the time taken for the stone to hit the surface of the lake? A. vsinθ g B. vcos θ g C. 2vsinθ g D. 2vcos θ g [1 mark] [1 mark] 24. A tennis ball is released from rest and falls vertically through a small distance in air. What is the change in the speed of the ball and [1 mark] the change in the acceleration of the ball as it falls? 25. The graph below shows the variation with time t of the velocity v of a car travelling in a straight line. [1 mark] Which graph shows the variation with t of the displacement s of the car? 26. A body moves in a straight line. In order for the equations for uniformly accelerated motion to be applied, which condition must be true? A. A constant net force acts on the body of fixed mass. B. A constant net force acts on the body. C. The body falls towards the surface of a planet. D. The body has an initial velocity of zero. [1 mark] 27. The graph shows the variation with time of the velocity of a truck of fixed mass. [1 mark] What can be deduced from the graph? A. The truck is always accelerating. B. The truck is always moving. C. The truck is always moving in one direction. D. The displacement of the truck after time t is zero. 28. A tennis ball is dropped from the top of a tall building. Air resistance is not negligible. Which graph shows the variation with time t of [1 mark] the displacement s of the ball? 29. A ball is thrown from point X and follows path XYZ. Air resistance is negligible. [1 mark] Which quantity is zero when the ball is at the highest point Y of the path? A. The horizontal component of the ball’s acceleration B. The vertical component of the ball’s acceleration C. The horizontal component of the ball’s velocity D. The kinetic energy of the ball 30. Two isolated spherical planets have the same gravitational potential at their surfaces. Which ratio must also be the same for the two [1 mark] planets? A. radius3 mass B. radius2 mass C. radius mass D. radius 31. The horizontal component vh and the vertical component vv of velocity of an object are shown on the graphs. Air resistance is negligible. These graphs could represent the motion of an object fired from a cliff A. vertically upwards. B. at an angle above the horizontal. C. horizontally. D. at an angle below the horizontal. [1 mark] 32. An object is dropped from rest above the Earth’s surface. Air resistance acts on the object. What is the variation of acceleration a with time t for the object? [1 mark] 33. The diagram shows the trajectory of an object projected in the absence of air resistance. [1 mark] The object is then projected with the same initial conditions but air resistance is taken into account. Which of the following is the trajectory when air resistance is taken into account? The original trajectory is shown as a dotted line. 34. The resultant force acting on an object of mass 5.0kg varies with time as shown. The object is initially at rest. [1 mark] What is the speed of the object after 1.0 s? A. 0.50ms–1 B. 1.0ms–1 C. 1.5ms–1 D. 2.0ms–1 35. A body moves on a straight line. The graphs show the variation of displacement with time. Which graph shows motion with negative [1 mark] acceleration? 36. Each side of a metal cube is measured to be 2.0 cm ± 0.20 cm. What is the absolute uncertainty in the calculated volume of the cube? [1 mark] A. ± 0.08 cm3 B. ± 0.60 cm3 C. ± 0.80 cm3 D. ± 2.4 cm3 37. A particle accelerates from rest. The graph shows how the acceleration a of the particle varies with time t. What is the speed of the particle at t=6.0s? A. 0.5 ms–1 B. 2.0 ms–1 C. 9.0 ms–1 D. 18 ms –1 [1 mark] 38. A ball of mass m is projected horizontally with speed v from a height h above the floor. Air resistance is negligible. [1 mark] The horizontal distance travelled by the ball to the point where it lands on the floor depends on A. m and h only. B. m and v only. C. h and v only. D. m, h and v. 39. A projectile is fired from level ground with speed v at an angle θ to the ground. Ignoring air resistance, which of the following is a correct expression for the maximum height reached by the projectile? A. v2sin2θ 2g B. v2cos 2θ 2g C. vsinθ g D. vcos θ g [1 mark] 40. A tennis ball is dropped from the top of a high building. Air resistance cannot be neglected. Which graph represents the variation with time t of the magnitude of the acceleration a of the ball before it hits the ground? [1 mark] 41. A ball is thrown from the top of a cliff. The initial magnitude of the velocity of the ball at time t=0 is V. The ball hits the sea at time t=T. Air resistance is negligible. [1 mark] Which graph shows how the vertical component of the velocity v of the ball varies with t as it falls to the sea? 42. An object, initially at rest, travels a distance d in a time t at a constant acceleration. What is the time taken for the object to travel 16d from rest at the same acceleration? A. 16t B. 8t C. 4t D. 2t [1 mark] 43. An object is released above the surface of Earth. Which of the following correctly describes the speed and acceleration before it reaches terminal speed? 44. [1 mark] An object of mass m is connected via a frictionless pulley to an object of mass M, where M > m. M rests on a horizontal frictionless [1 mark] surface What is the acceleration of the system? 45. The graph shows the variation with distance x of the magnitude of the net force F acting on a body initially at rest. [1 mark] Which of the following describes how the kinetic energy and the acceleration of the body change with distance? 46. Two identical balls are dropped from a tall building, one a few seconds after the other. Air resistance is not negligible. As the balls fall, the distance between the balls will A. decrease. B. increase. C. increase then remain constant. D. remain constant. [1 mark] 47. A ball of mass m is thrown horizontally from a cliff with initial velocity u. Air resistance is negligible. [1 mark] A change in which of the following will affect the horizontal distance travelled? A. m only B. u only C. both m and u D. neither m nor u 48. Which of the following is always true for an object moving in a straight line at constant speed? [1 mark] A. No forces act on the object. B. No resultant force acts on the object. C. The momentum of the object is zero. D. No work is being done on the object. 49. An object is thrown horizontally from the edge of a high crater on the Moon. The Moon has no atmosphere. Which of the following describes the changes, if any, to the horizontal and vertical components of the velocity of the object? [1 mark] 50. An object is thrown upwards leaving the thrower’s hand at time t=0. Which graph shows how speed v varies with t as the object rises and falls? [1 mark] 51. A ball is released at time t=0 above a horizontal surface. The graph shows the variation of velocity v with time. Which of the following shows the highest point of the ball after one bounce? [1 mark] 52. Balls X and Y are at the same height. X is projected horizontally at the same time that Y is dropped. Y is the same size as X but has [1 mark] half its mass. Ignoring air resistance, which statement is true? A. Y will hit the ground before X. B. Y will hit the ground after X. C. Y will hit the ground at the same time as X. D. The outcome can only be determined if the initial speed of X is known. 53. The velocity–time graph for an accelerating object that is traveling in a straight line is shown below. Which of the following is the change in displacement of the object in the first 5.0 seconds? A. 25.0 m B. 12.5 m C. 5.0 m D. 1.0 m [1 mark] 54. The graph shows the acceleration a of an object as time t varies. [1 mark] What is the magnitude of the change in the velocity of the object between 0 and 3 seconds? A. 5 ms –1 B. 10 ms –1 C. 20 ms –1 D. 30 ms –1 55. A gun fires a bullet of mass m at a horizontal velocity of v. Air resistance on the bullet is negligible. A change in which of the following will affect the time for the bullet to hit the ground? [1 mark] A. m only B. v only C. m and v D. neither m nor v 56. A stone is thrown vertically upwards from the surface of Earth. Which of the following quantities will not become zero while the stone[1 mark] is in the air? A. Speed B. Velocity C. Momentum D. Acceleration 57. An ice-hockey puck is slid along ice in a straight line. The puck travels at a steady speed of 20 ms force. How far does the puck travel in 2.5 s? A. 5 m B. 8 m C. 25 m D. 50 m –1 and experiences no frictional [1 mark] 58. A ball is thrown horizontally from the top of a high cliff. Air resistance is negligible. [1 mark] Which of the following correctly describes the changes, if any, to the ball’s vertical speed and horizontal speed? 59. Joseph runs along a long straight track. The variation of his speed v with time t is shown below. [1 mark] After 25 seconds Joseph has run 200 m. Which of the following is correct at 25 seconds? −2 −2 60. A car of mass 1000 kg accelerates on a straight, flat, horizontal road with an acceleration a = 0.3 m s . The driving force F on the [1 mark] car is opposed by a resistive force of 500 N. The net (resultant) force on the car is A. 200 N. B. 300 N. C. 500 N. D. 800 N. 61. The graph shows the variation with time t of the acceleration a of an object. Which of the following is the change in velocity of the object in the time interval 0 to 4s? A. -8ms-1 B. -4ms-1 C. +4ms -1 D. +8ms -1 [1 mark] 62. A car accelerates from rest. The acceleration increases with time. Which graph shows the variation with time t of the speed v of the [1 mark] car? 63. A stone is thrown from a cliff and it lands in the sea as shown below. Air resistance is negligible. Which of the following statements is correct whilst the stone is in motion? A. The vertical component of the stone’s displacement is constant. B. The horizontal component of the stone’s displacement is constant. C. The vertical component of the stone’s velocity is constant. D. The horizontal component of the stone’s velocity is constant. [1 mark] 64. A raindrop falling from rest at time t = 0 reaches terminal velocity. Which graph best represents how the speed v varies with time t? 65. The graph shows how the displacement d of an object varies with time t. The tangent to the curve at time t1 is also shown. Which of the following gives the speed of the object at point P? A. the gradient at P B. the shaded area C. 1 gradient at P D. d1 t1 [1 mark] [1 mark] 66. The diagram shows the path of a projectile that is launched with velocity v. Air resistance is negligible. [1 mark] A second projectile has double the mass of the first projectile and is launched with the same velocity. Air resistance is still negligible. Which of the following paths best represents the path of the projectile? (The original path is shown as a dotted line) 67. A car moves from X to Y along a semicircular path. The radius of the path is 250 m and the time taken to complete the trip is 50 s. [1 mark] Which of the following correctly shows the magnitude of the average velocity and the magnitude of the average speed? 68. The time taken for a stone dropped from rest to fall vertically through 16 m is 2.0 s. Based on these measurements, what is the best [1 mark] estimate for the acceleration of free fall? A. 4.0 m s− 2 B. 8.0 m s− 2 C. 9.8 m s− 2 D. 10 m s− 2 69. Which of the following quantities can be determined from a speed-time graph of a particle travelling in a straight line? A. Only the magnitude of the acceleration at a given instant B. Both the velocity and the acceleration at a given instant C. Only the distance travelled in a given time D. Both the distance travelled in a given time and the magnitude of the acceleration at a given instant 70. Two balls of different mass are dropped from the top of a tall building one after the other. The distance between the balls 71. A. increases with time. B. depends on the initial velocity only. C. remains constant. D. depends on the mass of the balls. The graph shows how the velocity of a particle varies with time. [1 mark] [1 mark] [1 mark] Which of the following graphs correctly shows how the acceleration of the particle varies with time? 72. Two cars, X and Y, are travelling towards a junction. The velocity of car X is VX and car Y is VY. Which of the following vectors represent the velocity of Y relative to X? [1 mark] 73. A football is kicked with an initial velocity u at an angle θ to the horizontal and reaches the ground t seconds later. [1 mark] Ignoring air resistance what is the range R of the football? 74. 75. A. ut B. ut cos θ C. ut sin θ D. ut tan θ A skydiver jumped out of an airplane. On reaching a terminal speed of 60 m s− 1, she opened her parachute. Which of the following [1 mark] describes her motion after opening her parachute? A. She went upwards for a short time, before falling to Earth at a speed of 60 m s− 1. B. She continued downwards at 60 m s− 1, but hit the ground with less force. C. She continued to fall but reached a new terminal speed of less than 60 m s− 1. D. She went upwards for a short time, before falling to Earth at a speed of less than 60 m s− 1. The graph is a speed versus time graph for an object that is moving in a straight line. The distance travelled by the object during the first 4.0 seconds is A. 80 m. B. 40 m. C. 20 m. D. 5 m. [1 mark] 76. An object moves in the x-y plane. The graphs below show how the component of its velocity Vx in the x-direction and the component of its velocity Vy in the y-direction, vary with time t. [1 mark] x-direction component y-direction component The particle is moving A. in a parabola. B. with simple harmonic motion. C. with constant velocity in a straight line. D. in a circle. © International Baccalaureate Organization 2018 International Baccalaureate® - Baccalauréat International® - Bachillerato Internacional® Printed for Oberoi International School