Question

A hydraulic cylinder with a radius of 0.0268 m has a piston on the left end and a safety valve at the right end. The safety valve is a circular opening with a radius of 0.00639 m, sealed with a disk. The disk is held in place by a spring (spring constant = 964 N/m) that is compressed 0.0111 m from its unstrained length. What is the magnitude of the minimum force that must be exerted on the piston in order to open the safety valve?