A ball of mass 100 g is moving with a velocity of 3 m/s towards east. A cube of mass 200 gram is moving towards west with a velocity of 7 m/s. If the collision is perfectly elastic, what is the final velocity of the ball in m/s?

MCQs on work, energy and power basics, work energy theorem, kinetic energy, friction, potential energy, variable force, spring potential energy, energy conservation law, power, collision and mechanical energy conservations.