Question

A block on a horizontal friction less plane is attached to a spring, as shown. The block oscillates along the x-axis with amplitude A. Which of the following statements about energy is correct? 

(A) The potential energy of the spring is at a minimum at x = 0.

(B) The potential energy of the spring is at a minimum at x = A.

(C) The kinetic energy of the block is at a minimum at x =0.

(D) The kinetic energy of the block is at a maximum at x = A.

(E) The kinetic energy of the block is always equal to the potential energy of the spring.

Answer 1

Correct option (A) The potential energy of the spring is at a minimum at x = 0.

There is no U_sp at position x=0 since there is no ∆x here so this is the minimum U location.