A box of mass 32.0 kg is sitting on a ramp which makes an angle of 24.0 degrees with respect to the horizontal. The coefficient of friction between the box and the ramp is 0.31. This box is connected by a massless string over a pulley at the top of the ramp to a second box with a mass of 42.0 kg suspended above the floor. Find the magnitude of the acceleration of the box on the ramp.