A 2.50 mass is pushed against a horizontal spring of force constant 26.0 on a frictionless air table. The spring is attached to the tabletop, and the mass is not attached to the spring in any way. When the spring has been compressed enough to store 15.0 of potential energy in it, the mass is suddenly released from rest.

a. Find the greatest speed the mass reaches?
b. What is the greatest acceleration of the mass?

1 answer

The potential energy of the block equals the kinetic energy of the block, so:

1/2kx^2=1/2mv^2

Because it gives you the potential energy already, we can find the velocity.

15.0J=1/2(2.50kg)v^2
v=3.46m/s

I can't help you with the second part, though. Sorry!