Calculate the velocity of a moving body of mass 5 kg whose linear momentum is 2.5 kg m s^-1.

A door is pushed, at a point whose distance from the hinges is 90 cm, with a force of 40 N. Calculate the moment of the force about the hinges.

At what height from the centre of the Earth the acceleration due to gravity will be 1/4^th of its value as at the Earth.