A boy was playing with a spongy ball, compressing and releasing it. The work done by the boy on the ball and the ball on the boy respectively at the time of compressing is:
Positive, Negative
At the time of compressing, the work done by the boy on the ball is positive as it causes the ball to squeeze which is in direction of force applied but the ball resists to change its shape and always tries to regain its original shape by opposing the force applied, therefore, the work done by the ball on the boy is negative.