Answer and discuss each problem in a detailed way.

The work done on a stretching a spring it to 3.50 cm from its equilibrium -- length is 14.0 J. (a) How much force is required to stretch it at that distance? (b) If a block of mass 2.75 kg moving at 4.8 ms hits and runs into the same spring at its unstretched iength, what is maximum compression of the spring? To compress a spring 5.0 cm from its unstretched length, 18.0 J of work must be done. {a} What is the magnitude of the force needed to stretch it to 7.5 cm? (b) How much work must be done in stretching this spring 7.5 cm from Its unstretched length