A light, ideal spring is fixed at one end on a frictionless horizontal surface and can be stretched as well as compressed.
Answer the following questions about the forces involved and the energy stored:
a. (a) State Hooke’s law for an ideal spring and clearly define each symbol used.
b. (b) Explain with reason why the force exerted by the spring is called a restoring force. Your answer should specifically refer to the sign convention adopted for displacement.
c. (c) Show that the elastic potential energy stored in the spring remains non-negative whether the spring is stretched or compressed.