A worker inside a truck at point A applies a force to rope ABC to slowly lower a box C d...

A worker inside a truck at point A applies a force to rope ABC to slowly lower a box C down a ramp DE. The box has 400N weight and slides without friction on the ramp, and the pulley at B is frictionless. For the position of the box given below, determine the force the worker must apply to the rope and the reaction between the box and ramp. Neglect the size of the box and pulley.

The box is 3/4 the distance from point D to point E.