Rupert is investigating the properties of a light (effectively massless) spring. He has attached one end of the spring to a fixed horizontal rod and allowed the spring to hang vertically. The free end of the spring has a small hook to which Rupert can attach various masses. An Experiment to Determine the Spring Constant Part A Rupert finds that if he attaches a 470.0 gram mass to the hook, and then very slowly lowers the mass with his hand until the force on the mass by the spring is as large as the weight of the mass, that the spring stretches by 36.0 cm . What is the spring constant of Rupert's spring