The students must conduct an experiment to determine the magnitude of the force exerted on the block when the block is at a position of A2, where A is the amplitude of oscillation for the block-spring system. For each trial, the students attach blocks of different mass m to the spring, stretch the spring a known distance A, release the system from rest, measure the period of oscillation T, and then measure the maximum velocity v of the system. How should students use a graph to determine the magnitude of the force under consideration?