A 2kg block is attached to a horizontal spring of force constant 200N m−1. The spring is compressed 0.10m from its natural length and released from rest on a frictionless surface. Calculate the speed of the block as it passes through the equilibrium position.
(a) 3.2m s−1
(b) 4.5m s−1
(c) 1.0m s−1
(d) 0.71m s−1