According to the third law of motion, action and reaction:

A. Always act on the same body but in opposite directions

B. Always act on different bodies in opposite directions

C. Have same magnitudes and directions

D. Act on either body at normal to each other

An object of mass 2 kg is sliding with a constant velocity of 4 m/s on a frictionless horizontal table. The force required to keep this object moving with the same velocity is:

A. 32 N B. 0 N

C. 2 N D. 8 N

The physical quantity which makes it easier to accelerate a small car than a large is measures in the unit of:

A. m/s B. kg

C. kg m/s D. kg m/s²

The unit of measuring momentum of a moving body is:

A. m s^-1 B. kg m s^-1

C. kg m s^-2 D. Nm² kg^-2

A boy of mass 50 kg standing on ground exerts a force of 500 N on the ground. The force exerted by the ground on the boy will be:

A. 50 N B. 25000 N

C. 10 N D. 500 N