set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

Assertion (A):
A man standing on a completely frictionless surface can propel himself by whistling.
Reason (R) :
If no external force acts on a system, its momentum cannot change.

a) A is true but R is false

b) Both A and R are true but R is not a correct explanation of A

c) Both A and R are true and R is the correct explanation of A

d) A is false but R is true

Question : 2

A gymnast takes turns with her arms & legs stretched. When she pulls her arms and legs

a) the angular velocity stays constant

b) the moment of inertia decreases

c) the angular velocity decreases

d) the angular momentum increases

Question : 3

Kepler’s second law (law of area) is nothing but a statement of

a) conservation of angular momentum

b) conservation of linear momentum

c) work energy theorem

d) conservation of energy

Question : 4

Force is the product of

a) Weight and velocity

b) Mass and acceleration

c) Mass and velocity

d) Weight and acceleration

Question : 5

A man jumped at a speed of 5 metre per second from a stationary boat and the boat moved off with the speed of 0.5 metre per second. How many times is the mass of the boat greater than that of the man?

a) 2.5 times

b) 4.5 times

c) 5.5 times

d) 10 times

Question : 6

An athlete diving off a high springboard can perform a variety of exercises in the air before entering the water below. Which one of the following parameters will remain constant during the fall?

a) The athlete’s kinetic energy

b) The athlete’s moment of inertia

c) The athlete’s linear momentum

d) The athlete’s angular momentum