Hello s7bAssuming that Hooke's Law is still obeyed when the spring becomes compressed, the motion is Simple Harmonic, with centre the original equilibrium position, and amplitude 4 inches. That's the answer to the first question.

The tension in the spring is proportional to the extension. When the extension is 3 inches, tension = weight of body = mg. So when extension = 7 inches, tension = . So, if we resolve vertically at the point of maximum extension:

, taking g = 32

With the usual notation, the equation of motion is

And we know that when feet, . So we can now work out the value of

Now the velocity, displacement and amplitude are related by

The maximum velocity is when . So max velocity = . And the time it takes to reach its highest point ishalfthe period of a complete oscillation. And that period is

Can you take it from here?

Grandad