A block-spring system moves with simple harmonic motion and has an amplitude of A.

a. What is the magnitude of the displacement, x, when the kinetic energy equals three times the potential energy stored in the spring.
b. Suppose at a certain instant the kinetic energy is twice the elastic potential energy. Write an equation describing this situation, using only the variables for mass m, velocity v, spring constant k, and position x.
c. Using the results of parts a and b, and the conservation of energy equation, find the positions x of the object when its kinetic energy equals twice the potential energy stored in the spring (this answer should be in terms of A only)