Force and Motion MCQs

Question 1

A 7.0 kg bowling ball experiences a net force of 5.0 N. Its acceleration will be:

Accepted Answer

0.71 m/s2

Answer

35 m/s2

Answer

7.0 m/s2

Answer

5.0 m/s2

Question 2

To improve the jumping record, the long jumper should jump at an angle of:

Accepted Answer

45o

Answer

30°

Answer

60o

Answer

90o

Question 3

If the time of flight of a projectile is 10 seconds. The range is 500m. The maximum height attained by it will be:

Accepted Answer

125 m

Answer

50 m

Answer

100 m

Answer

150 m

Question 4

One fielder throws a ball and in 4 seconds it reaches to another player. So, the maximum height reached by the ball above the point of projection would be about:

Accepted Answer

20 m

Answer

10 m

Answer

7.5 m

Answer

5 m

Question 5

Two bodies are projected with the same velocity. If one is projected at an angle of 30o and the other at an angle of 60o to the horizontal, the ratio of the maximum heights reached is:

Accepted Answer

1 : 3

Answer

3 : 1

Answer

1 : 2

Answer

2 : 1

Question 6

Two balls are projected from the top of a tower of height 120 m, one with an initial upward velocity of 36 km/h and the other with an initial downward velocity of 36 km/h. The speed of each ball just before hitting the ground is: (take g = 10 m/s2 )

Accepted Answer

50 m/s, 50 m/s

Answer

50 m/s, 70 m/s

Answer

70 m/s, 50 m/s

Answer

50 m/s, 5√2m/s

Question 7

A ball thrown by one player reaches the other in 2 sec. The maximum height attained by the ball above the point of projection will be about:

Accepted Answer

5 m

Answer

10 m

Answer

7.5 m

Answer

2.5 m

Question 8

A projectile is fired at 30o with momentum p. Neglecting friction, the change in kinetic energy when it returns to the ground will be:

Accepted Answer

Zero

Answer

30%

Answer

60%

Answer

100%

Question 9

A passenger is walking on a walkalator (horizontal escalator) at a speed of 6 km/hr relative to the escalator. He starts from point P on the ground and reaches point Q on the ground. The walkalator is moving at 3 km/hr relative to the ground in the direction of point Q. The distance PQ is 120 m. The time taken by him to reach point Q is:

Accepted Answer

48 s

Answer

16 s

Answer

32 s

Answer

72 s

Question 10

Can an object maintain uniform velocity when its acceleration is not zero?

Accepted Answer

No, impossible

Answer

Yes, but only if the acceleration is in the direction of the velocity

Answer

Yes, but only if the acceleration is opposite to the direction of the velocity

Answer

Yes, if the acceleration is perpendicular to the velocity

Question 11

A particle is projected with velocity (3iˆ+4jˆ) m/s from horizontal. What will be the height attained by it when the velocity becomes perpendicular to acceleration?

Accepted Answer

0.8 m

Answer

5 m

Answer

0.4 m

Answer

1.6 m

Question 12

A projectile is thrown with velocity v at an angle θ with the horizontal. When the projectile is at a height equal to half of the maximum height, the vertical component of the velocity of projectile is:

Accepted Answer

vsinθ/√2

Answer

vsinθ

Answer

3vsinθ

Answer

vsinθ/√3

Question 13

Two projectiles A and B are thrown with the same speed such that A makes angle q with the horizontal and B makes angle q with the vertical, then:

Accepted Answer

Both may have same time of flight

Answer

Both must have same time of flight

Answer

Both must achieve same maximum height

Answer

A must have more horizontal range than B

Question 14

A flag is mounted on a car moving due North with a velocity of 20 km/hr. Strong winds are blowing due East with a velocity of 20 km/hr. The flag will point in the direction:

Accepted Answer

South - East

Answer

East

Answer

North - East

Answer

South - West

Question 15

From a tower of height h, a particle is projected horizontally with velocity u, and another is thrown down with the same velocity u. If the time taken by these is t1 and t2, what is true?

Accepted Answer

t1 > t2

Answer

t1 = t2

Answer

t1 < t2

Answer

t1 = 3t2

Question 16

What is the average velocity of a projectile between the instants it crosses half the maximum height? It is projected with a speed u at an angle θ with the horizontal:

Accepted Answer

ucosθ

Answer

usinθ

Answer

utanθ

Answer

u

Question 17

An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960m. When it is vertically above a point A on the ground, a bomb is released from it. The bomb strikes the ground at point B. The distance AB is:.

Accepted Answer

3.33 km

Answer

1200 m

Answer

0.33 m

Answer

33 km

Question 18

If the ratio of the horizontal range and the maximum height reached is 4:1. Then, if the body is thrown horizontally, what will be the projection angle?

Accepted Answer

75o

Answer

30o

Answer

60o

Answer

90o

Question 19

A particle of mass 1 kg is projected at an angle of 30˚ with the horizontal with velocity v = 40 m/s. The change in linear momentum of the particle after time t = 1s will be: (g = 10 m/s2)

Accepted Answer

10 kg-m/s

Answer

7.5 kg-m/s

Answer

15 kg-m/s

Answer

20 kg-m/s

Question 20

The velocity of the projectile is increased by 2 %. If other factors remain unchanged, then what will be the percentage change in the maximum height attained?

Accepted Answer

4 %

Answer

8 %

Answer

2 %

Answer

1 %

Free Force and Motion MCQs with Answers