A vertical spring is suspended from a rigid support. A 0.30kg mass is attached to its lower end and allowed to come to rest at a new equilibrium position. The upward direction is taken to be positive.
At a certain instant during subsequent oscillations the mass is 0.080m below the equilibrium position and moving upward with non-zero speed. The spring constant is 60N/m. Neglect any resistive forces.
(a) Determine the magnitude and algebraic sign of the force the spring exerts on the mass at that instant. Justify how you assign the sign based on the chosen positive direction.
(b) Compare the spring force you found in part (a) with the gravitational force acting on the mass. Indicate which force is larger in magnitude and state the direction of the net force.
(c) Using your answer to part (b), explain whether the mass is speeding up or slowing down at that instant, and why.