A metal sphere suspended from a vertical spring is performing lightly-damped oscillations in a container of viscous oil.

Which of the following statements is/are correct regarding the viscous damping force acting on the sphere?

1. The damping force is in the same direction as the gravitational force when the sphere is moving vertically upwards.
2. The magnitude of the damping force is maximum when the magnitude of the acceleration of the sphere is maximum.
3. The rate of dissipation of mechanical energy by the damping force is zero at the displacement amplitudes of the oscillation.