A block attached to a spring with spring constant 20 N/m is initially at rest on a frictionless horizontal surface. The block is gently pulled to the right, and then released from rest when the spring is stretched by 0.2 m. When the block passes through the equilibrium position for the first time, the time is set to be zero and the block's speed is 2.0 m/s. a) Find the mass of the block. b) Find the position(s) when the potential energy is 1/6 of the kinetic energy. c) Find the equation for the motion of the block in the form as x(t) = Acos (wt + 4). d) Find the first time when the velocity of the block is 1.0 m/s.

A block attached to a spring with spring constant 20 N/m is initially at rest on a frictionless horizontal surface. The block is gently pulled to the right, and then released from rest when the spring is stretched by 0.2 m. When the block passes through the equilibrium position for the first time, the time is set to be zero and the block's speed is 2.0 m/s. a) Find the mass of the block. b) Find the position(s) when the potential energy is 1/6 of the kinetic energy. c) Find the equation for the motion of the block in the form as x(t) = Acos (wt + 4). d) Find the first time when the velocity of the block is 1.0 m/s.