Chapter - 2
Motion in Straight Line
MCQs __________________________________
Q.1.The displacement in meters of a body varies with time t in second as y = t2 – t – 2. The
displacement is zero for a positive of t equal to
(a) 1 s (b) 2 s
(c) 3 s (d) 4 s
Q.2.A boy starts from a point A, travels to a point B at a distance of 3 km from A and returns to
A. If he takes two hours to do so, his speed is
(a) 3 km/h (b) zero
(c) 2 km/h (d) 1.5 km/h
Q.3.A 180 meter long train is moving due north at a speed of 25 m/s. A small bird is flying due
south, a little above the train, with a speed of 5 m/s. The time taken by the bird to cross the train
is
(a) 10 s (b) 12 s
(c) 9 s (d) 6 s
Q.4. A boy starts from a point A, travels to a point B at a distance of 1.5 km and returns to A. If
he takes one hour to do so, his average velocity is
(a) 3 km/h (b) zero
(c) 1.5 km/h (d) 2 km/h
Q.5. A body starts from rest and travels with uniform acceleration on a straight line. If its
velocity after making a displacement of 32 m is 8 m/s, its acceleration is
(a) 1 m/s² (b) 2 m/s²
(c) 3 m/s² (d) 4 m/s²
Q.6. Which one of the following is the unit of velocity?
(a) kilogram (b) meter
(c) m/s (d) second
Q.7. A body starts from rest and travels for t second with uniform acceleration of 2 m/s². If the
displacement made by it is 16 m, the time of travel t is
(a) 4 s (b) 3 s
(c) 6 s (d) 8 s
Q.8. The dimensional formula for speed is
(a) T-1(b) LT-1
(c) L-1T-1(d) L-1T
Q.9. The dimensional formula for velocity is
(a) [LT] (b) [LT-1]
(c) [L2T] (d) [L-1T]
Q.10. A body starts from rest and travels with an acceleration of 2 m/s². After t seconds its
velocity is 10 m/s . Then t is
(a) 10 s (b) 5 s
(c) 20 s (d) 6 s
Q.11. A boy starts from a point A, travels to a point B at a distance of 1.5 km and returns to A. If
he takes one hour to do so, his average velocity is
(a) 3 km/h (b) zero
(c) 1.5 km/h (d) 2 km/h
Q.12. A body starts from rest. If it travels with an acceleration of 2 m/s², its displacement at the
end of 3 seconds is
(a) 9 m (b) 12 m
(c) 16 m (d) 10 m
Q.13. A body starts from rest and travels with uniform acceleration of 2 m/s². If its velocity is v
after making a displacement of 9 m, then v is
(a) 8 m/s (b) 6 m/s
(c) 10 m/s (d) 4 m/s
Q.14. A body starts from rest and travels with an acceleration of 2 m/s². After t seconds its
velocity is 10 m/s. Then t is
(a) 10 s (b) 5 s
(c) 20 s (d) 6 s
Q.15. A body starts from rest and travels for five seconds to make a displacement of 25 m if it
has travelled the distance with uniform acceleration a then a is
(a) 3 m/s² (b) 4 m/s²
(c) 2 m/s² (d) 1 m/s²
Q.16: A boy moves on a circular distance of radius R. Starting from a point A he moves to a
point B which is on the other end of the diameter AB. The ratio of the distance travelled to the
displacement made by him is
(a) ∏/2 (b) ∏
(c) 2∏ (d) 4∏
Q.17. The dimensional formula for acceleration is
(a) [LT2] (b) [LT-2]
(c) [L2T] (d) [L2T2]
Q.18. A body starts from rest and travels with uniform acceleration a to make a displacement of
6 m. If its velocity after making the displacement is 6 m/s, then its uniform acceleration a is (a)
6 m/s² (b) 2 m/s²
(c) 3 m/s² (d) 4 m/s²
Q.19. Which one of the following is the unit of velocity?
(a) kilogram (b) meter
(c) m/s (d) second
Q.20. The displacement in meters of a body varies with time t in second as y = t2 – t – 2. The
displacement is zero for a positive of t equal to
(a) 1 s (b) 2 s
(c) 3 s (d) 4 s
Q.21. What is the acceleration if the body starts from rest and travels a distance of ‘S’ m in 2
seconds?
(a) (2/3)S m/s2 (b) (3/2) S m/s2
(c) (1/3)S m/s2 (d) (S/2) m/s2
Q.22. What is the ratio of the average acceleration during the intervals OA and AB in the
velocity-time graph as shown below?
(a) ½ (b) ⅓
(c) 1 (d) 3
.Q23. A body covers 16, 18, 20, 22 meters in 5th, 6th, 7th and 8th seconds respectively. Which
of the following statements is true about the body?
(a) The body moves with a uniform velocity from rest
(b) The body from rest moves with uniform acceleration
(c) The body moves with an initial velocity and moves with uniform acceleration (d) The
body moves with an initial velocity and then moves with uniform velocity .Q24. What
can be said about the displacement of the body if it covers a distance of zero? (a) It is
zero (b) It cannot be zero
(c) It may or may not be zero (d) It is negative
.Q.25. An athlete finishes a round of circular track of radius R in 40 sec. What is his
displacement at the end of 2 min 20 sec?
(a) 2R (b) 2πR
(c ) 7π (d ) Zero
Q.26. Which of the following is not possible for a body in uniform
motion? (a)
(b)
(c) Both (a) & (b)
(d) None of the above
Q.27. If a car travels (2/5) th of the total distance with a speed 10m/s and (3/5) th of the distance
with a speed 20m/s. The average speed is given by
(a) 15 m/s (b) 200 m/s
(c) 133/7 m/s (d) 5 m/s
Q.28. A man leaves home for a cycle ride and comes back home after an half-an-hour ride
covering a distance of one km. What is the average velocity of the ride?
(a) 10 kms-1(b) ½ kms-1
(c) 2 kms-1(d) Zero
Q.29. A bird flies with a speed of 10 km/hr and a car moves with uniform speed 8 km/hr. Both
start from B to A at the same instant (BA = 40 km). The bird after reaching A flies back
immediately to meet the approaching car. Once it reaches the car, it flies back to A. The bird
repeats this until both the car and the bird reach A simultaneously. What is the total distance
flown by the bird?
(a) 80 km (b) 50 km
(c) 40 km (d) 30 km
Q.30. Elephants A, B and C move with a constant speed in the same direction along a straight
line as shown in the figure. The speed of the elephant A is 5 m/s and the speed of the elephant C
is 10 m/s. Initially, the separation between A and B is d and between B and C is also d. When B
catches C, the separation between A and C becomes 3d. What will the speed of B be?
(a) 5 m/s (b) 7.5 m/s
(c) 15 m/s (d) 20 m/s
Q.31. Which of the following remains constant if a body travels with constant
acceleration? (a) Time (b) Velocity
(c) Displacement (d) None of the above
Q.32. Given here is a velocity-time graph of the motion of a body. What is the distance travelled
by the body during the motion?
(a) (1/2)(OA+AB)×BC (b) (1/2)(OA+BC)×OC
(c) (½)(OC+AB)×AD (d) (1/2)(AD+BE)×OC
Q.33. Which of the following graphs gives the equation x=v0t+12at2
(a)
(b)
(c)
(d) None of the above
Q.34. What does the displacement of the particle shown in the graph
indicate?
(a) It indicates a constant velocity
(b) It indicates a constant acceleration
(c) It indicates that the particle starts with a constant velocity and is accelerated
(d) It indicates that the motion is retarded and the particle stops
Q.35. When a body is dropped from a tower, then there is an increase in its
(a) mass (b) velocity
(c) acceleration (d) potential energy
Q36. The dimensional formula for acceleration is
(a) [LT2] (b) [LT-2]
(c) [L2T] (d) [L2T2]
Q37. Which one of the following is the unit of velocity?
(a) kilogram (b) meter
(c) m/s (d) second
Q38. The ratio of the numerical values of the average velocity and average speed of a body is
(a) unity or less (b) less than unity
(c) unity (d) unity or more
Q39. A particle is moving with a constant speed along straight line path. A force is not required
to
(a) change its direction (b) increase its speed
(c) decrease its momentum (d) keep it moving with uniform velocity Q.40. The slope
of velocity-time graph for motion with uniform velocity is equal to
(a) zero (b) final velocity
(c) initial velocity (d) none of these
Q41. Which one of the following is the unit of acceleration?
(a) m/s (b) m/s²
(c) km/hr (d) cm/s
Q.42. A boy starts from a point A, travels to a point B at a distance of 3 km from A and returns
to A. If he takes two hours to do so, his speed is
(a) 3 km/h (b) zero
(c) 2 km/h (d) 1.5 km/h
Q43. The distance travelled by an object is directly proportional to the time taken. Its
acceleration
(a) increases (b) decreases
(c) becomes zero (d) remains constant
Q44. A body starts from rest and travels for t second with uniform acceleration of 2 m/s². If the
displacement made by it is 16 m, the time of travel t is
(a) 4 s (b) 3 s
(c) 6 s (d) 8 s
Q45. A body starts from rest and travels with an acceleration of 2 m/s². After t seconds its
velocity is 10 m/s. Then t is
(a) 10 s (b) 5 s
(c) 20 s (d) 6 s
Q46. Which of the following is a one dimensional motion ?
(a) Motion of train running on a straight track
(b) Motion of satellite
(c) Motion of air particle
(d) Motion of snake
Q47. If the displacement of an object is zero, then what can we say about its distance covered?
(a) It is negative (b) It is must be zero
(c) It cannot be zero (d) It may or may not be zero
Q48. A boy moves on a circular distance of radius R. Starting from a point A he moves to a point
B which is on the other end of the diameter AB. The ratio of the distance travelled to the
displacement made by him is
(a) ∏/2 (b) ∏
(c) 2∏ (d) 4∏
Q49. A body starts from rest. If it travels with an acceleration of 2 m/s², its displacement at the
end of 3 seconds is
(a) 9 m (b) 12 m
(c) 16 m (d) 10 m
Q50. Which of the following can be zero, when a particle is in motion for some time?
(a) Displacement (b) None of these
(c) Distance (d) Speed
Q51. The acceleration of a moving object can be found from
(a) area under displacement-time graph
(b) slope of displacement-time graph
(c) area under velocity-time graph
(d) slope of velocity-time graph
Q52. The location of a particle has changed. What can we say about the displacement and the
distance covered by the particle?
(a) Neither can be zero (b) One may be zero
(c) Both may be zero (d) One is +ve, other is –ve
Q53. If the displacement-time graph of an object is parallel to the time-axis, then it represents
that the object is :
(a) at rest (b) in uniform motion
(c) in acceleration motion (d) none of the above
ASSERTION AND REASON TYPE QUESTIONS
Directions: The question numbers 1 to 20 consist of two statements one labeled Assertion (A) and the other
labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given
below.
(a) If both A and R are true and R is the correct explanation of A
(b) If both A and R are true but R is NOT the correct explanation of A
(c) If A is true but R is false
(d) If A is false and R is also false
1). A : It is not possible to have constant velocity and variable acceleration.
R : Accelerated body cannot have constant velocity.
2). A : The direction of velocity of an object can be reversed with constant acceleration.
R: A ball projected upward reverse its direction under the effect of gravity.
3). A : When the velocity of an object is zero at an instant, the acceleration need not to be zero at that instant.
R : In motion under gravity, the velocity of body is zero at the top-most point.
4). A : A body moving with decreasing speed may have increased acceleration.
R : The speed of body decreases when acceleration of body is opposite to velocity.
5). A : For a moving particle distance can never be negative or zero.
R : Distance is a scalar quantity and never decreases with time for moving object.
6). A : If speed of a particle is never zero then it may have zero average speed.
R : The average speed of a moving object in a closed path is zero.
7). A : The magnitude of average velocity in an interval can never be greater than average speed in that interval.
R : For a moving object distance travelled is greater than or equal to magnitude of displacement 8). A : The
area under acceleration-time graph is equal to velocity of object.
R : For an object moving with constant acceleration position-time graph is a straight line.
9). A : The motion of body projected under the effect of gravity without a resistance is uniformly accelerated
motion.
R : If a body is projected upwards or downwards, then the direction of acceleration is downward.
10). A : The relative acceleration of two objects moving under the effect of gravity, only is always zero,
irrespective of direction of motion .
R : The acceleration of object moving under the effect of gravity have acceleration always in the downward
direction and is independent from size and mass object.
11). A : In the presence of air resistance, if the ball is thrown vertically upward then time of ascent is less than the
time of descent.
R : Force due to air friction always acts opposite to the motion of body.
12). A : Average velocity can be zero, but average speed of a moving body cannot be zero in any finite time
interval.
R : For a moving body displacement can be zero but distance can never be zero.
13). A : For a particle moving in a straight line its acceleration must be either parallel or antiparallel to
velocity. R : A body moving along a curved path may have constant acceleration.
14). A : A body can have acceleration even if its velocity is zero at that instant.
R : The body will momentarily at rest when it reverses its direction of motion.
15). A : When a body is dropped or thrown horizontally from the same height, it would reach the ground at the
same time.
R : Horizontal velocity has no effect on the vertically direction.
16). A : Displacement of a body may be zero, when distance travelled by it is not
zero. R : The displacement is the larger distance between initial and final positions.
17). A: Retardation is directly opposite to the velocity.
R : Retardation is equal to the time rate of decrease of speed.
18). A : A body having a non-zero acceleration can have constant velocity.
R : Acceleration is the rate of change of velocity.
19). A : Two balls of different masses are thrown vertically upward with same speed. They will passthrough the
point of projection in the downward direction with the same speed.
R : The maximum height and downward velocity attained at the point of projection are independent of the
mass of the ball.
20). A : An object can have constant speed but variable velocity.
R ; Speed is a scalar but velocity is a vector quantity.
Case Study Based Questions
Following questions are case study-based questions. Each question has five sub parts of multiple
choice questions. Attempt any four sub parts from each question. Each sub part of question
carries 1 mark.
Q.1. In the absence of air resistance, all bodies falls with same same acceleration near the surface
of the earth. This motion of a body falling towards the earth from a small height is called free
fall. The acceleration with which a body falls is called acceleration due to gravity and it is
denoted by g.
(i) For a freely falling body, which of the following equation is incorrect.
(a) h-ut =(1/2) gt2 (b) v2 – u2 =2gh
(c ) h = (1/2) ut +gt2 (d) (v-u)/g = t
(ii) The maximum height attained by a body thrown vertically upward with initial velocity u
is (a) h=u2/2g (b) h=u/2g
(c ) h=u2/g (d) h= 2u2/g
(iii) The time of ascent of a body thrown vertically upward with initial velocity u
is (a) t= u/2g (b) t= u/g
(c) t= u2/g (d) t= u/g2
(iv) The total time of flight to come back to the point of projection of a body thrown vertically
upward with initial velocity u is
(a) t= 2u/3g (b) t= u/2g
(c ) t= 2u/g (d) t= u2/2g
(v) Velocity of fall at the point of projection of a body thrown vertically upward with initial
velocity u is
(a) v = u (b) v = 2u
(c ) v = 3u (d) v = 4u
Q.2 The acceleration of an object is said to be uniform acceleration if its velocity changes by
equal amount in equal interval of time, however small these time intervals may be. A particle is
moving with uniform acceleration in x-direction, the displacement x of particle varies with time t
as x = 4t2-15t+25. m
(i) The position of particle at t = 0,
(a) 14 m. (b) 18 m
(c) 20 m (d) 25 m
(ii) Velocity of particle at t = 2 s
(a) -15 m/s (b) 1 m/s
(c) 3 m/s (d) 31 m/s
(iii) Acceleration of particle at t = 2 s
(a) 0 ms-2 (b) 8 ms-2
(c) 10 ms-2 (d) 20 ms-2
(iv) The velocity of particle will become zero at time t equal to
(a) 2.975 s. (b) 1.875 s.
(c) 2 s. (d) 1 s.
(v) The particle has a uniform acceleration ‘a ‘when
(a) acceleration does not depend on time t (b) acceleration depends on time t
(c) velocity changes by unequal amount in equal interval of time,
(d) None of these
Q.3.The time rate of change of position of the object in any direction is called speed of the object
If an object covers equal distances in equal intervals of time, then its speed is called uniform
speed andifit covers unequal distances in equal intervals of time, then its speed is called non
uniform or variable speed. The ratio of the total distance travelled by the object to the total time
taken is called average speed of the object. The speed may be positive or zero but never negative.
The speed-time graph of a particle moving along a fixed direction is shown in following Fig.
(i) Distance travelled by the particle between 0 to 10 seconds
(a) 60 m (b) 50 m
(c) 120 m (d) zero
(ii) Average speed between time interval 0 to 10 s
(a) 12 m/s (b) 6 m/s
(c) 10 m/s (d) 60 m/s
(iii) The time when the speed was minimum
(a) at t = 0 s and t = 5 s (b) at t = 5 s and t = 20 s
(c) at t = 5 s and t = 10 s (d) at t = 0 s and t = 10 s
(iv) The time when speed was maximum
(a) t = 0 s (b) t = 5 s(c) t = 10 s
(d) t = 12 s
(v) Speed is positive at time interval
(a) t = 0 to t = 5 s (b) t = 5 to t = 10 s
(c) t = 0 to t = 10 s (d) All of these
