A particle, P, of mass 3 kg is attached to one end of a light, elastic spring. The other end of the spring is attached to a ceiling at the point A. The spring has natural length 1.6m and modulus of elasticity 45N. The system rests in equilibrium with the spring vertical.

a. Find the extension in the spring.

b. The particle is pulled down a further 0.6m and released. Find the distance of the particle below the point A when it first comes to instantaneous rest.