A spring attached to a mass is at rest in the initial position (not shown). The spring is compressed in position A and is then released, as shown in position B. Which equation describes conservation of energy in position A?

Explanation:

When the spring is compressed, it is compressed to its amplitude (whereas equilibrium is the spring's natural length with no mass attached to it and displacement is the spring's reaction to a mass hung on the end of it without any "extra" pushing or pulling on the mass). It is at the amplitude where the spring experineces max potential energy, which is choice 2, E = mph