1.       Design a helical extension spring to handle a dynamic load that varies from 60 lb to 75 lb over 0.5-in working deflection. Use music wire and standard hooks. The forcing frequency is 1 200 rpm. Infinite life is desired. Minimize the package size.

2.       Choose appropriate safety factors against fatigue, yielding, and surging. Design a straight-ended helical torsion spring for a static load of 50 N-m at a deflection of 60° with a safety factor of 2. Specify all parameters necessary to manufacture the spring. State all assumptions.