Determine the magnitude of force F as a function of time, which must be applied to the end...

Determine the magnitude of force F as a function of time, which must be applied to the end of the cord at A to raise the hook H with a constant speed v = 0.4 m/s. Initially the chain is at rest on the ground. Neglect I he mass of the cord and the hook. The chain has a mass of 2 kg/in.