Physics simple question

Question

A block on the end of a spring is pulled to position x=A and released. Through what total distance does it travel in one full cycle of its motion __???

A)A/2;

B)A;

C)2A;

D) 4A;

Answer 1

The correct answer is 4A, which is (D).  Here is why:

 

Suppose it starts from rest at +A.  If total energy is conserved, it will reach -A on the opposite side of the equilibrium point, come to instantaneous rest, reverse direction, and move back to +A, completing 1 cycle.  The total travel distance out and back is 2A + 2A = 4A.