restricted block on spring

Question

A block of mass m = 4.5 kg slides back and forth on a frictionless horizontal track. It is attached to a spring with a relaxed length of L = 3 m and a spring constant k = 17 N/m. The spring is initially vertical, which is its the relaxed postion but then the block is pulled d = 3 m to one side.

1) By what length is the spring extended?

2) What is the potential energy stored in the spring?

3) The block is released. What is the maximum speed it attains?

4) Let's change the problem a bit. When the spring is vertical (hence, unstretched), the block is given an initial speed equal to 1.9 times the speed found in part (c). How far from the initial point does the block go along the floor before stopping?

5) What is the magnitude of the acceleration of the block at this point (when the spring is stretched farthest)?

Answer 1