A block of mass 2 kg is attached to a horizontal, massless spring of force constant 100 N/m. The block is displaced by 0.1 m from its equilibrium position and then released. Calculate the speed of the block when it passes through the equilibrium position.

Options:

a) 2 m/s b) 4 m/s c) 1 m/s d) 10 m/s e) 6 m/s