Tiêu đề 03. Motion in a Staright line Med.pdf ✅

1. A branch of physics dealing with motion without considering its causes is known as (a) Statics (b) Dynamics (c) Kinematics (d) Hydrodynamics 2. Which of the following statements is incorrect? (a) Path length is a scalar quantity whereas displacement is a vector quantity (b) The magnitude of displacement is always equal to the path length traversed by an object over a given time interval (c) The displacement depends only on the end points whereas path length depends on the actual path followed (d) The path length is always positive whereas displacement can be positive, negative and zero 3. The three initial and final positions of a man on the x-axis are give as (1) (-3 m, 7 m) (2) (7m, -3 m) (3) (-7m, 3m) Which pair gives the negative displacement? (a) (1) (b) (2) (c) (3) (d) (1) and (3) 4. A drunkard is walking along a straight road. He takes 5 steps forward and 3 steps backward and so on. Each step is 1 m long and takes 1 s. There is a pit on the road 11 m away from the starting point. The drunkard will fall into the pit after (a) 21 s (b) 29 s (c) 31 s (d) 37 s 5. The numerical ratio of distance to displacement is (a) Always equal to one (b) Always less than one (c) Always greater than one (d) Equal to or more than one 6. If a man goes 10 m toward north and 20 m toward east, then his displacement is (a) 22.5 m (b) 25 m (c) 25.5 m (d) 30 m 7. Which of the following statements is incorrect? (a) Displacement is independent of the choice of origin of the axis (b) Displacement may or may not be equal to the distance travelled (c) When a particle returns to its starting point, its displacement is not zero (d) Displacement does not tell the nature of the actual motion of a particle between the points 8. Which of the following graphs represents the position-time graph of a particle moving with negative velocity (a) (b) (c) (d) 9. Which of the following changes when a particle is moving with uniform velocity? (a) Position (b) Speed (c) Velocity (d) Acceleration 10. Which of the following statements are incorrect? (i) Average velocity is path length divided by time interval (ii) In general, speed is greater than the magnitude of the velocity (iii) A particle moving in a given direction with a non-zero velocity can have zero speed (iv) The magnitude of average velocity is the average speed (a) (ii) and (iii) (b) (ii) and (iv) (c) (i), (iii) and (iv) (d) All four 11. A car is moving along a straight line OP as shown in the figure. It moves from O to P in 18 s and returns from P to Q in 6 s. Which of the following statements is not correct regarding the motion of the car? (a) The average speed of the car in going from O to P and come back to Q is 20 m s-1 (b) The average velocity of the car in going from O to P and come back to Q is 10 m s-1 (c) The average speed of the car in going from O to P and come back to O is 20 m s-1 (d) The average velocity of the car in going O to P and come back to O is 20 m s-1 12. The area under velocity-time graph for a particle in a given interval of time represents (a) Velocity (b) Acceleration (d) Work done (d) Displacement 13. A cyclist moving on a circular track of radius 40 m completes half a revolution in 40 s. Its average velocity is (a) Zero (b) 1 4 ms  − (c) 2 m s-1 (d) 1 8 ms −  14. Which of the following graphs cannot possibly represent one dimensional motion of a particle? (a) (i) and (ii) (b) (ii) and (iii) (c) (i), (ii) and (iii) (d) All four 15. Speedometer of a car measures (a) Average speed (b) Average velocity (c) Instantaneous speed (d) Instantaneous velocity 16. The velocity of the particle at any time t is given by 1 v 2t(3 t)ms − = − At what time is its velocity maximum? (a) 2 s (b) 3 s (c) s 3 2 (d) s 2 3 17. A particle moves with uniform velocity. Which of the following statements about the motion of the particle is true? (a) Its speed is zero (b) Its acceleration is zero (c) Its acceleration is opposite to the velocity (d) Its speed may be variable
18. The speed-time graph of a particle moving along a fixed direction as shown in the figure. The distance traversed by the particle between t = 0 s to t = 10 s is (a) 20 m (b) 40 m (c) 60 m (d) 80 m 19. The displacement-time graph of a moving particle is as shown in the figure. The instantaneous velocity of the particle is negative at the point. (a) C (b) D (c) E (d) F 20. Speedometer measures the speed of the car in (a) ms-1 (b) km h-1 (c) cm s-1 (d) km min-1 21. Figure shows the displacement (x)-time (t) graph of the particle moving on the x-axis. (a) The particle is at rest (b) The particle is continuously going along x-direction (c) The velocity of the particle increases upto time 0 t and then becomes constant (d) The particle moves at a constant velocity up to a time 0 t and then stops 22. The motion of a body is given by the equation 6 3v dt dv = − where v is the speed in m s-1 and t is time in s. The body is at rest at t = 0. The speed varies with time as (a) 3t v (1 e ) − = − (b) v 2(1 e ) −3t = − (c) 2t v (1 e ) − = + (d) v 2(1 e ) −2t = + 23. Position-time graph for motion with zero acceleration is (a) (b) (c) (d) 24. The slope of the tangent drawn on velocity-time graph at any instant of time is equal to the instantaneous (a) Acceleration (b) Velocity (c) Impulse (d) Momentum 25. Match the Column I with Column II Column I Graph Column II Haracteristic (A) (p) Has v > 0 and a < 0 throughout (B) (q) Has x > 0 throughout and has a point with v = 0 and a point with a = 0 (C) (r) Has a point with zero displacement for t >0 (D) (s) Has v < 0 and a > 0 (a) (A) →(p),(B) →(q),(C) →(s),(D) →(r) (b) (A) →(q),(B) →(p),(C) →(r),(D) →(s) (c) (A) →(s),(B) →(r),(C) →(q),(D) →(p) (d) (A) →(r),(B) →(q),(C) →(s),(D) →(p) 26. The area under acceleration-time graph represents the (a) Initial velocity (b) Final velocity (c) Change in velocity (d) Distance travelled 27. The velocity-displacement graph of a particle is as shown in the figure Which of the following graphs correctly represents the variation of acceleration with displacement? (a) (b) (c) (d) 28. For the one-dimensional motion, described by X = t − sin t (a) x(t) > 0 for all t > 0 (b) v(t) > 0 for all t > 0 (c) a(t) > 0 for all t > 0 (d) All of these
29. Which of the following statements is not correct regarding the motion of a particle in a straight line? (a) x-t graph is a parabola, if motion is uniformly accelerated (b) v-t is a straight line inclined to the time axis, if motion is uniformly accelerated (c) x-t graph is a straight line inclined to the time axis if motion is uniform and acceleration is zero (d) v-t graph is a parabola if motion is uniform and acceleration is zero 30. A particle starts from point A moves along a straight line path with an acceleration given by a = p – qx where p, q are constants and x is distance from point A. The particle stops at point B. The maximum velocity of the particle is (a) q p (b) q p (c) q p (d) p q 31. The displacement of a body is given to be proportional to the cube of time elapsed. The magnitude of the acceleration of the body is (a) Increasing with time (b) Decreasing with time (c) Constant but not zero (d) Zero 32. The speed-time graph of a particle moving along a fixed direction is shown in the figure. The distance traversed by the particle between t = 2 s the particle t = 6 s is (a) 26 m (b) 36 m (c) 46 m (d) 56 m 33. The given acceleration-time graph represents which of the following physical situations? (a) A cricket ball moving with a uniform speed is hit with a bat for a very short time interval (b)A ball is falling freely from the top of a tower (c) A car moving with constant velocity on a straight road (d) A football ball is kicked into the air vertically upwards 34. The velocity of a particle at an instant is 1 10ms − . After 3 s its velocity will becomes 1 16ms − . The velocity at 2 s, before the given instant will be (a) 1 6ms − (b) 1 4ms − (c) 1 2ms − (d) 1 1ms − 35. A player throws a ball vertically upwards with velocity u. At highest point, (a) Both the velocity and acceleration of the ball are zero (b) The velocity of the ball is u but its acceleration is zero (c) The velocity of the ball is zero but its acceleration is g (d) The velocity of the ball is u but its acceleration is g 36. The distances traversed during equal intervals of time by a body falling from rest stand to one another in the same ratio as the odd numbers beginning with unity that is, 1 : 3 : 5 :7 :.... This law was established by (a) Galileo Galilei (b) Isaac Newton (c) Johannes Kepler (d) Albert Einstein 37. In the question number 59, the time taken by the ball to reach the ground is (a) 2 s (b) 3 s (c) 5 s (d) 7 s 38. Free fall of an object in vacuum is a case of motion with (a) Uniform velocity (b) Uniform acceleration (c) Variable acceleration (d) Uniform speed 39. Which of the following statements is not correct? (a) The zero velocity of a body at any instant does not necessarily imply zero acceleration at that instant (b) The Kinematic equation of motions are true only for motion in which the magnitude and the direction of acceleration are constants during the course of motion (c) The sign of acceleration tells us whether the particle’s speed is increasing or decreasing (d) All of these 40. A body A starts from rest with an acceleration 1 a . After 2 seconds, another body B starts from rest with an acceleration 2 a . If they travel equal distances in the 5th second, after the start of A, then the ration 1 2 a : a is equal to (a) 5 : 9 (b) 5 : 7 (c) 9 : 5 (d) 9 : 7 41. Which of the following graphs represents the velocity-time variation of an object falls freely under gravity? (a) (b) (c) (d) 42. Which of the following equations does not represent the kinematic equations of motion? (a) v = u + at (b) 2 at 2 1 S = ut + (c) 2 at 2 1 S = vt + (d) v u 2aS 2 2 − = where, u = initial velocity of a body v = final velocity of the body a = uniform acceleration of the body S = distance travelled by the body in time t 43. A body initially at rest is moving with uniform acceleration a. Its velocity after n seconds is v. The displacement of the body is fast 2 s is
(a) n 2v(n −1) (b) n v(n −1) (c) n v(n +1) (d) n 2v(n +1) 44. A girl standing on a stationary lift (open from above) throws a ball upwards with initial speed 50 m s-1 . The time taken by the ball to return to her hands is (Take g = 10 m s-2 ) (a) 5 s (b) 10 s (c) 15 s (d) 20 s 45. It is a common observation that rain clouds can be at about 1 km altitude above the ground. If a rain drop falls from such a height freely under gravity, then what will be its speed in km h -1 ?(Take g = 10 m s-2 ) (a) 510 (b) 610 (c) 710 (d) 910 46. The distances covered by a freely falling body in its first, second, third, ......, nth seconds of its motion (a) Forms an arithmetic progression (b) Forms a geometric progression (c) Do not form any well defined series (d) Form a series corresponding to the difference of square root of the successive natural numbers 47. A body starting from rest moves along a straight line with a constant acceleration. The variation of speed (v) with distance (s) is given by (a) (b) (c) (d) 48. A car moving with a speed of 50 km h-1 can be stopped by brakers after at least 6 m. If the same car is moving at a speed of 100 km h-1 the minimum stopping distance is (a) 6 m (b) 12 m (c) 18 m (d) 24 m 49. An object falling through a fluid is observed to have acceleration given by a = g – bv where g = gravitational acceleration and b is constant. After a long time of release, it is observed to fall with constant speed. The value of constant speed is (a) b g (b) g b (c) bg (d) b 50. A body covers 20 m, 22 m, 24 m, in 8th, 9th and 10th seconds respectively. The body starts (a) From rest and moves with uniform velocity (b) From rest and moves with uniform acceleration (c) With an initial velocity and moves with uniform acceleration (d) With an initial velocity and moves with uniform velocity 51. Stopping distance of a moving vehicle is directly proportional to (a) Square of the initial velocity (b) Square of the initial acceleration (c) The initial velocity (d) The initial acceleration 52. Which one of the following represents displacement-time graph of two objects A and B moving with zero relative velocity? (a) (b) (c) (d) 53. In the above que., the speed of the child running opposite to the direction of motion of the belt is (a) 4 km h-1 (b) 5 km h-1 (c) 9 km h-1 (d) 13 km h-1 54. In the above que., time taken by the child to go from father to mother and back to father is (a) 10 s (b) 20 s (c) 30 s (d) 40 s 55. Among the four graphs, there is only one graph for which average velocity over the time interval (0. T) can vanish for a suitably chosen T. Which one is its? (a) (b) (c) (d) 56. A lift is coming from 8th floor and is just about to reach 4th floor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct? (a) x  0,v  0, a  0 (b) x  0,v  0,a  0 (c) x  0,v  0,a  0 (d) x  0,v  0,a  0 57. In one dimensional motion, instantaneous speed v satisfies 0 0 v v .   (a)The displacement in time T must always take non-negative values (b) The displacement x in time T satisfies 0 0 −   v T x v T. (c) The acceleration is always a non-negative number (d) The motion has no turning points 58. A vehicle travels half the distance L with speed 1 v and other half with speed 2 v , then its average speed is