Give Reasons

1. A rubber ball rebounds on striking the surface of the floor.

When the ball strikes the floor,the floor hits back with the same amount of force because for every action there is an equal and opposite reaction.

2.An inflated balloon lying on the surface of the floor moves forward when pierced with a needle

When we pierce the balloon,the air is released from the balloon in the backward direction.This pushes the balloon in the forward direction with an equal amount of force.This in accordance with Newton's third law of motion.

3.It is difficult to walk on a slippery surface but easier to walk on rough surface.

On a slippery surface friction is reduced as a result reaction force is very less and an individual is unable to walk.On a hard surface action is related to reaction and it is easier to walk.

4. A gun recoils after firing a bullet

When a gun is fired it exerts a forward force on the bullet.The bullet exerts an equal and opposite reaction force on the gun.This results in the recoil of the gun.