JEE Physics Motion In A Straight Line MCQs Set A

Question. A body in one dimensional motion has zero speed at an instant. At that instant, it must have
(a) Zero velocity
(b) Non-zero velocity
(c) Zero acceleration
(d) Non-zero acceleration

Answer: A

Question. Consider the motion of the tip of the second hand of a clock. In one minute (R be the length of second hand), its
(a) Displacement is zero
(b) Distance covered is zero
(c) Distance covered is 2R
(d) None of this

Answer: A

Question. The position of a body moving along x-axis at time t is given by x = (t² – 4t + 6) m. The distance travelled by body in time interval t = 0 to t = 3 s is
(a) 5 m
(b) 7 m
(c) 4 m
(d) 3 m

Answer: A

Question. If a particle is moving along straight line with increasing speed, then
(a) Its acceleration may be decreasing
(b) Its acceleration is negative
(c) Its acceleration is positive
(d) All of these

Answer: A

Question. At any instant, the velocity and acceleration of a particle moving along a straight line are v and a. The speed of the particle is increasing if
(a) v > 0, a > 0
(b) v < 0, a > 0
(c) v > 0, a < 0
(d) v > 0, a = 0

Answer: A

Question. A particle moves along x-axis with speed 6 m/s for the first half distance of a journey and the second half distance with a speed 3 m/s. The average speed in the total journey is
(a) 4 m/s
(b) 2 m/s
(c) 4.5 m/s
(d) 5 m/s

Answer: A

Question. If magnitude of average speed and average velocity over a time interval are same, then
(a) The particle must move in a straight line without turning back
(b) The particle must be at rest
(c) The particle must move with non-zero acceleration
(d) The particle must move with zero acceleration

Answer: A

Question. If a body is moving with constant speed, then its acceleration
(a) May be variable
(b) Must be zero
(c) May be uniform
(d) All of these

Answer: A

Question. When the velocity of body is variable, then
(a) All of these
(b) Its acceleration may be constant
(c) Its speed may be constant
(d) Its average acceleration may be constant

Answer: A

Question. An object is moving with variable speed, then
(a) Its velocity must be variable
(b) Its velocity may be constant
(c) Its velocity may be zero
(d) Its acceleration may be zero

Answer: A

Question. The position of a particle moving along x-axis is given by x = 10t – 2t2. Then the time (t) at which it will momently come to rest is
(a) 2.5 s
(b) 5 s
(c) 10 s
(d) 0

Answer: A

Question. A particle starts moving with acceleration 2 m/s². Distance travelled by it in 5th half second is
(a) 2.25 m
(b) 1.25 m
(c) 6.25 m
(d) 30.25 m

Answer: A

Question. A train starts from rest from a station with acceleration 0.2 m/s2 on a straight track and then comes to rest after attaining maximum speed on another station due to retardation 0.4 m/s2. If total time spent is half an hour, then distance between two stations is [Neglect length of train]
(a) 216 km
(b) 512 km
(c) 728 km
(d) 1296 km

Answer: A

Question. A body is projected vertically upward direction from the surface of earth. If upward direction is taken as positive, then acceleration of body during its upward and downward journey are respectively
(a) Negative, negative
(b) Positive, positive
(c) Negative, positive
(d) Positive, negative

Answer: A

Question.  A particle start moving from rest state along a straight line under the action of a constant force and travel distance x in first 5 seconds. The distance travelled by it in next five seconds will be
(a) 3 x
(b) 4 x
(c) 2 x
(d) x

Answer: A

Question. A body is projected vertically upward with speed 40 m/s. The distance travelled by body in the last second of upward journey is [take g = 9.8 m/s² and neglect effect of air resistance
(a) 4.9 m
(b) 9.8 m
(c) 12.4 m
(d) 19.6 m

Answer: A

Question. A body is projected vertically upward with speed 10 m/s and other at same time with same speed in downward direction from the top of a tower. The magnitude of acceleration of first body w.r.t. second is {take g = 10 m/ s²}
(a) Zero
(b) 10 m/s²
(c) 5 m/s²
(d) 20 m/s²

Answer: A

Question. The position of a particle moving along x-axis given by x = (–2t³ + 3t² +5)m. The acceleration of particle at the instant its velocity becomes zero is
(a) –6 m/s²
(b) Zero
(c) –12 m/s²
(d) 12 m/s²

Answer: A

Question. A car travelling at a speed of 30 km/h is brought to rest in a distance of 8 m by applying brakes. If the same car is moving at a speed of 60 km/h then it can be brought to rest with same brakes in
(a) 32 m
(b) 64 m
(c) 16 m
(d) 4 m

Answer: A

Question. A body is thrown vertically upwards and takes 5 seconds to reach maximum height. The distance travelled by the body will be same in
(a) 1st and 10th second
(b) 2nd and 8th second
(c) 4th and 6th second
(d) All of these

Answer: A

Question. A ball is dropped from a bridge of 122.5 metre above a river. After the ball has been falling for two seconds, a second ball is thrown straight down after it. Initial velocity of second ball so that both hit the water at the same time is
(a) 26.1 m/s
(b) 9.8 m/s
(c) 55.5 m/s
(d) 49 m/s

Answer: A

Question. A balloon starts rising from ground from rest with an upward acceleration 2 m/s². Just after 1 s, a stone is dropped from it. The time taken by stone to strike the ground is nearly
(a) 0.7 s
(b) 1 s
(c) 1.4 s
(d) 0.3 s

Answer: A

Question. A boy throws a ball into air after 2 second. The next ball is thrown when the velocity of first ball is zero. How high do the ball rise above his hand? [Take g = 9.8 m/s²]
(a) 19.6 m
(b) 29.4 m
(c) 9.8 m
(d) 4.9 m

Answer: A

Question. A car moving with speed v on a straight road can be stopped with in distance d on applying brakes. If same car is moving with speed 3v and brakes provide half retardation, then car will stop after travelling distance
(a) 9 d
(b) 18 d
(c) 3 d
(d) 6 d

Answer: A

Question. If average velocity of particle moving on a straight line is zero in a time interval, then
(a) Velocity of particle must be zero at an instant
(b) Acceleration of particle may be zero
(c) Velocity of particle may be never zero in the interval
(d) Average speed of particle may be zero in the interval

Answer: A

Question. A ball is dropped from an elevator moving upward with acceleration ‘a’ by a boy standing in it. The acceleration of ball with respect to [Take upward direction positive]
(a) Both
(b) Ground is – g
(c) Boy is – (g + a)
(d) None of these

Answer: A

Question. A ball dropped from the top of tower falls first half height of tower in 10 s. The total time spend by ball in air is [Take g = 10 m/s²]
(a) 14.14 s
(b) 15.25 s
(c) 12.36 s
(d) 17.36 s

Answer: A

Question. A ball is projected vertically upwards. Its speed at half of maximum height is 20 m/s. The maximum height attained by it is [Take g = 10 ms²]
(a) 40 m
(b) 25 m
(c) 15 m
(d) 35 m

Answer: A

Question. A particle travels half of the distance of a straight journey with a speed 6 m/s. The remaining part of the distance is covered with speed 2 m/s for half of the time of remaining journey and with speed 4 m/s for the other half of time. The average speed of the particle is
(a) 4 m/s
(b) 3/4 m/s
(c) 5 m/s
(d) 3 m/s

Answer: A

Question. A body thrown vertically up with initial velocity 52 m/s from the ground passes twice a point at h height above at an interval of 10 s. The height h is (g = 10 m/s²)
(a) 10.2 m
(b) 11.2 m
(c) 15 m
(d) 12 m

Answer: A

Question. Two balls are projected upward simultaneously with speeds 40 m/s and 60 m/s. Relative position (x) of second ball w.r.t. first ball at time t = 5 s is [Neglect air resistance].
(a) 100 m
(b) 120 m
(c) 80 m
(d) All of these

Answer: A