What is normal for a spring that obeys hook's law ?

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

What are the necessary conditions for fusion?