mechanics (mass, force, acceleration, work, energy, momentum, velocity) - Category wise Question and Answer Practice Test with Solutions

Question : 26

A rubber ball dropped from 24 m height loses its kinetic energy by 25%. What is the height to which it rebounds.

a) 18 m

b) 12 m

c) 6 m

d) 24 m

Question : 27

Two persons do the same amount of work, one in 10 s and the other in 20 s. Find the ratio of the power used by the first person to that by the second person.

a) 5 : 2

b) 2 : 1

c) 6 : 4

d) 4 : 3

Question : 28

A cannon after firing recoils due to

a) Newton’s third law of motion

b) backward thrust of gases produced

c) conservation of energy

d) Newton’s first law of motion

Question : 29

Time period of a simple pendulum inside a satellite orbiting earth is

a) T

b) ∞

c) zero

d) 2 T

Question : 30

ML²T ^–2 are dimensions of

a) momentum

b) moment of force

c) force

d) power