CBSE Class 11 Motion in Straight Line Worksheet C

Question. A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 seconds for every circular lap. The average velocity and average speed for each circular lap respectively is
(a) 10 m/s, 0
(b) 0, 0
(c) 0, 10 m/s
(d) 10 m/s, 10 m/s.
Answer. C

Question. A car moves a distance of 200 m. It covers the first half of the distance at speed 40 km/h and the second half of distance at speed v. The average speed is 48 km/h.
The value of v is
(a) 56 km/h
(b) 60 km/h
(c) 50 km/h
(d) 48 km/h. 
Answer. B

Question. A bus travelling the first one-third distance at a speed of 10 km/h, the next one-third at 20 km/h and at last one-third at 60 km/h. The average speed of the bus is
(a) 9 km/h
(b) 16 km/h
(c) 18 km/h
(d) 48 km/h. 
Answer. C

Question. A car covers the first half of the distance between two places at 40 km/h and another half at 60 km/h.The average speed of the car is
(a) 40 km/h
(b) 48 km/h
(c) 50 km/h
(d) 60 km/h.
Answer. B

Question. The displacement ‘x’ (in meter) of a particle of mass ‘m’ (in kg) moving in one dimension under the action of a force, is related to time ‘t’ (in sec) by t = x + 3. The displacement of the particle when its velocity is zero, will be
(a) 4 m
(b) 0 m (zero)
(c) 6 m
(d) 2 m
Answer. B

Question. The position x of a particle with respect to time t along x-axis is given by x = 9t2 – t³ where x is in metres and t in seconds. What will be the position of this particle when it achieves maximum speed along the +x direction?
(a) 54 m
(b) 81 m
(c) 24 m
(d) 32 m. 
Answer. A

Question. A particle moves along a straight line OX. At a time t (in seconds) the distance x (in metres) of the particle from O is given by x = 40 + 12t – t³. How long would the particle travel before coming to rest?
(a) 16 m
(b) 24 m
(c) 40 m
(d) 56 m 
Answer. A

Question. The displacement x of a particle varies with time t as x = ae–at + bebt, where a, b, a and b are positive constants. The velocity of the particle will
(a) be independent of b
(b) drop to zero when a = b
(c) go on decreasing with time
(d) go on increasing with time.
Answer. D

Question. A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = bx–2n, where b and n are constants and x is the position of the particle. The acceleration of the particle as a function of x, is given by
(a) –2β²x^{–2n + 1}
(b) –2nβ² e^{–4n + 1}
(c) –2nβ² x^{–2n – 1}
(d) –2nβ² x^{–4n – 1}
Answer. B

Question. The motion of a particle along a straight line is described by equation x = 8 + 12t – t³ where x is in metre and t in second. The retardation of the particle when its velocity becomes zero is
(a) 24 m s^–2
(b) zero
(c) 6 ms^–2
(d) 12 ms^–2
Answer. D

Question. A particle moves a distance x in time t according to equation x = (t + 5)^–1. The acceleration of particle is proportional to
(a) (velocity)^3/2
(b) (distance)²
(c) (distance)^–2
(d) (velocity)^2/3
Answer. A

Question. Motion of a particle is given by equation s = (3t³ + 7t² + 14t + 8) m. The value of acceleration of the particle at t = 1 sec is
(a) 10 m/s²
(b) 32 m/s²
(c) 23 m/s²
(d) 16 m/s².
Answer. B

Question. The position x of a particle varies with time, (t) as x = at² – bt³. The acceleration will be zero at time t is equal to
(a) a/3b
(b) zero
(c) 2a/3b
(d) a/b
Answer. A

Question. A particle moves along a straight line such that its displacement at any time t is given by s = (t³ – 6t² + 3t + 4) metres. The velocity when the acceleration is zero is
(a) 3 m/s
(b) 42 m/s
(c) –9 m/s
(d) –15 m/s
Answer. C

Question. A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is (g = 10 m/s²)
(a) 360 m
(b) 340 m
(c) 320 m
(d) 300 m
Answer. D

Question. A boy standing at the top of a tower of 20 m height drops a stone. Assuming g = 10 m s^–2, the velocity with which it hits the ground is
(a) 10.0 m/s
(b) 20.0 m/s
(c) 40.0 m/s
(d) 5.0 m/s 
Answer. B

Question. A ball is dropped from a high rise platform at t = 0 starting from rest. After 6 seconds another ball is thrown downwards from the same platform with a speed v. The two balls meet at t = 18 s. What is the value of v ? (Take g = 10 m/s²)
(a) 75 m/s
(b) 55 m/s
(c) 40 m/s
(d) 60 m/s
Answer. A

Question. A particle starts its motion from rest under the action of a constant force. If the distance covered in first 10 seconds is S₁ and that covered in the first 20 seconds is S₂, then
(a) S₂ = 3S₁
(b) S₂ = 4S₁
(c) S₂ = S₁
(d) S₂ = 2S₁
Answer. B

Question. A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 m s^–1 to 20 m ^s–1 while passing through a distance 135 m in t second. The value of t is
(a) 12
(b) 9
(c) 10
(d) 1.8
Answer. B

Question. The distance travelled by a particle starting from rest and moving with an acceleration 4/3 m s⁻² , in the third second is
(a) 10/3 m
(b) 19/3 m
(c) 6 m
(d) 4 m
Answer. A

Question. Two bodies A (of mass 1 kg) and B (of mass 3 kg) are dropped from heights of 16 m and 25 m, respectively.
The ratio of the time taken by them to reach the ground is
(a) 4/5
(b) 5/4
(c) 12/5
(d) 5/12 
Answer. A

Question. A ball is thrown vertically upward. It has a speed of 10 m/sec when it has reached one half of its maximum height. How high does the ball rise?
(Take g = 10 m/s²)
(a) 10 m
(b) 5 m
(c) 15 m
(d) 20 m 
Answer. A

Question. A man throws balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time ?
(Given g = 9.8 m/s²)
(a) more than 19.6 m/s
(b) at least 9.8 m/s
(c) any speed less than 19.6 m/s
(d) only with speed 19.6 m/s
Answer. A

Question. A particle is thrown vertically upward. Its velocity at half of the height is 10 m/s, then the maximum height attained by it (g = 10 m/s²)
(a) 8 m
(b) 20 m
(c) 10 m
(d) 16 m. 
Answer. C

Question. A car moving with a speed of 40 km/h can be stopped by applying brakes after atleast 2 m. If the same car is moving with a speed of 80 km/h, what is the minimum stopping distance?
(a) 4 m
(b) 6 m
(c) 8 m
(d) 2 m 
Answer. C

Question. If a car at rest accelerates uniformly to a speed of 144 km/h in 20 s, it covers a distance of
(a) 1440 cm
(b) 2980 cm
(c) 20 m
(d) 400 m
Answer. D

Question. A body dropped from a height h with initial velocity zero, strikes the ground with a velocity 3 m/s. Another body of same mass dropped from the same height hwith an initial velocity of 4 m/s. The final velocity of second mass, with which it strikes the ground is
(a) 5 m/s
(b) 12 m/s
(c) 3 m/s
(d) 4 m/s. 
Answer. A

Question. The water drop falls at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at instant the first drop touches the ground. How far above the ground is the second drop at that instant?
(a) 3.75 m
(b) 4.00 m
(c) 1.25 m
(d) 2.50 m. 
Answer. A

Question. The velocity of train increases uniformly from 20 km/h to 60 km/h in 4 hours. The distance travelled by the train during this period is
(a) 160 km
(b) 180 km
(c) 100 km
(d) 120 km
Answer. A

Question. A body starts from rest, what is the ratio of the distance travelled by the body during the 4th and 3rd second ?
(a) 7/5
(b) 5/7
(c) 7/3
(d) 3/7
Answer. A

Question. A body dropped from top of a tower fall through 40 m during the last two seconds of its fall. The height of tower is (g = 10 m/s2)
(a) 60 m
(b) 45 m
(c) 80 m
(d) 50 m 
Answer. B

Question. What will be the ratio of the distance moved by a freely falling body from rest in 4th and 5th seconds of journey ?
(a) 4 : 5
(b) 7 : 9
(c) 16 : 25
(d) 1 : 1. 
Answer. B

Question. A car is moving along a straight road with a uniform acceleration. It passes through two points P and Q separated by a distance with velocity 30 km/h and 40 km/h respectively. The velocity of the car midway between P and Q is
(a) 33.3 km/h
(b) 20 2 km/h
(c) 25 2 km/h
(d) 35 km/h.
Answer. C

Question. A bus is moving with a speed of 10 m s^–1 on a straight road. A scooterist wishes to overtake the bus in 100 s.If the bus is at a distance of 1 km from the scooterist, with what speed should the scooterist chase the bus?
(a) 40 m s^–1
(b) 25 m s^–1
(c) 10 m s^–1
(d) 20 m s^–1
Answer. D

Question. A train of 150 metre length is going towards north direction at a speed of 10 m/s. A parrot flies at the speed of 5 m/s towards south direction parallel to the railways track. The time taken by the parrot to cross the train is
(a) 12 s
(b) 8 s
(c) 15 s
(d) 10 s 
Answer. D
 

1. Under what condition the displacement and the distance of a moving object will have the same magnitude?

2. What is the shape of the displacement time graph for uniform linear motion?

3. Figure shows a displacements time graph. Comment on the sign of velocities at point P, Q, R, S and T.

4. Draw displacement time graph for a uniformly accelerated motion? What is its shape?

5. The displacement x of a particle moving in one dimension under the action of constant force is related to the time by the equation where x is in meters and t is in seconds. Find the velocity of the particle at (1) t = 3s (2) t = 6s.

6. A balloon is ascending at the rate of 4.9m/s. A pocket is dropped from the balloon when situated at a height of 245m. How long does it take the packet to reach the ground? What is its final velocity?

7. A car moving on a straight highway with speed of 126km/hr. is brought to stop within a distance of 200m. What is the retardation of the car (assumed uniform) and how long does it take for the car to stop?

8. Establish s = ut + 1/2 at from velocity time graph for a uniform accelerated motion?

9. (a) Define the term relative velocity?

(b) Write the expression for relative velocity of one moving with respect to another body when objects are moving in same direction and are moving in opposite directions?

(c) A Jet airplane traveling at the speed of 500km/hr ejects its products of combustion at the speed of 1500km/h relative to the Jet plane. What is the speed of the latter with respect to an observer on the ground? 

10. Define (i) v = u + at (ii) V² – u² = 2as by calculus method

Click on link below to download CBSE Class 11 Motion in Straight Line Worksheet C.