Force and Motion MCQs

Question 1

A car in motion hits and gets crashed into a tree trunk, what is NOT conserved?

Accepted Answer

Kinetic energy alone

Answer

Momentum alone

Answer

Momentum and kinetic energy both

Answer

Neither kinetic energy nor momentum

Question 2

A stone is dropped from a cliff. The graph (Position or velocity versus time) which best represents motion when it falls:

Accepted Answer

A straight-line graph with a positive slope (Velocity vs. Time)

Answer

A curved graph with increasing slope (Position vs. Time)

Answer

A straight-line graph with a constant slope (Position vs. Time)

Answer

A curved graph with an increasing slope (Velocity vs. Time)

Question 3

A 40kg body starting from rest falls through a vertical distance of 125cm to the ground. The velocity of the body just before it hits the ground is:

Accepted Answer

5 m/s

Answer

250 m/s

Answer

(250)½ m/s

Answer

25 m/s

Question 4

A person's life was saved in a car accident due to airbags system. During that car accident, airbags expanded in front of head of that person. If that car was not equipped with airbags then movement of head would be stopped by windshield in much faster time. Airbags saved life because it:

Accepted Answer

Causes much smaller force for longer time

Answer

Causes much greater force for longer time

Answer

Causes much greater force for smaller time

Answer

Causes much smaller force for smaller time

Question 5

Which of the following statements is absolutely correct: I. Forces can stop or make objects move faster II. Forces can change the direction of movement

Accepted Answer

Both I and II

Answer

I

Answer

II

Answer

Neither I nor II

Question 6

Which one of the following is true in the case of inelastic collision?

Accepted Answer

Total energy Conserved, Kinetic Energy Not conserved, Momentum Conserved

Answer

Total energy Conserved, Kinetic Energy Conserved, Momentum Conserved

Answer

Total energy Conserved, Kinetic Energy Conserved, Momentum Not conserved

Answer

Total energy Not conserved, Kinetic Energy Not conserved, Momentum Conserved

Question 7

An aeroplane is flying horizontally with a velocity of 10 m/s and at a height of 1960 m. 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 (ignoring air resistance)

Accepted Answer

200 m

Answer

100 m

Answer

400 m

Answer

2 km

Question 8

A ball is projected horizontally from the top of a cliff on the surface of the earth with a speed of 40 ms−1. Assuming that there is no air resistance, what will its speed be 3 s later?

Accepted Answer

50ms−1

Answer

30 ms−1

Answer

40 ms−1

Answer

60ms−1

Question 9

A 4 kg body is thrown vertically upward from the ground with a velocity of 5 ms−1. Its kinetic energy just before hitting the ground is

Accepted Answer

50 J

Answer

25 J

Answer

75 J

Answer

100 J

Question 10

If momentum is increased by two times K.E increases by

Accepted Answer

Four times

Answer

Two times

Answer

3 times

Answer

Remains

Question 11

Consider three-point charges A, B, and C as shown in the figure. If the resultant force on charge A due to charge B and charge C is 0.024 N, the direction of resultant force will be:

Accepted Answer

Vertical to the surface the charges are placed

Answer

Towards Charge A

Answer

Towards Charge B

Answer

Towards Charge C

Question 12

A javelin is thrown by Arshad Nadeem at a projection angle of 45 degrees with an initial velocity of 30 m/s, the range of the javelin will be: (Consider g = 10 m/s²):

Accepted Answer

90m

Answer

85m

Answer

95m

Answer

100m

Question 13

At a stop light, a truck traveling at 15 m/s passes a car as it starts from rest. The truck travels at constant velocity, and the car accelerates at 3 m/s². How much time does the car take to catch up to the truck?

Accepted Answer

10 s

Answer

5 s

Answer

15 s

Answer

20 s

Question 14

Which one of the following statements is correct for an object released from rest?

Accepted Answer

The average velocity during the first second of time is 4.9 m/s

Answer

During each second, the object falls 9.8 m

Answer

The acceleration changes by 9.8 m/s² every second

Answer

The object falls 9.8 m during the first second of time

Question 15

A machine gun fires a bullet of mass 40 g with a velocity 1200 m/s. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can he fire per second at the most?

Accepted Answer

Three

Answer

One

Answer

Four

Answer

Two

Question 16

If the force on a rocket moving with a velocity of 300 m/s is 210 N, then the rate of combustion of fuel is:

Accepted Answer

0.7 kg/s

Answer

1.4 kg/s

Answer

7 kg/s

Answer

10.7 kg/s

Question 17

A man is standing on a weighing machine placed in a lift. When stationary, his mass is recorded as 40 kg. If the lift is moved upwards with an acceleration of 2ms-2, then the weight recorded in the machine will be: (g = 10 ms-2)

Accepted Answer

48 kg

Answer

32 kg

Answer

40 kg

Answer

42 kg

Question 18

The mass of a lift is 500 kg. What will be the tension in its cable when it is moving down under the effect of gravity only? (g = 10 m/s2)

Accepted Answer

0 N

Answer

5000 N

Answer

50 N

Answer

1000 N

Question 19

A block of mass 10 kg is suspended through two light spring balances as shown in the figure: What will be the reading on the scales?

Accepted Answer

Both the scales will read 10 kg

Answer

Both the scales will read 5 kg

Answer

The upper scale will read 10 kg and the lower will read zero

Answer

The readings may be anything but their sum will be 10 kg

Question 20

In the given diagram, with what force must the man pull the rope to hold the plank in position? The weight of the man is 60 x 9.81 N. Neglect the weights of the plank, rope, and pulley.

Accepted Answer

15 x 9.81 N

Answer

30 x 9.81 N

Answer

60 x 9.81

Answer

120 x 9.81 N

Free Force and Motion MCQs with Answers