4.4 A man is dragging a Figure E4.4 trunk up the loading ramp of a mover's truck. The ramp has a slope angle of 20.0, and the man pulls upward with a force F whose direction makes an angle of 30.0 with the ramp (Fig. E4.4). (a) How large a force F is necessary for the component Fx parallel to the 30.0 20.0 ramp to be 60.0 N? (b) How large will the component Fy perpendi- cular to the ramp then be? 4.5 Two dogs pull horizontally on ropes attached to a post; the angle between the ropes is 60.0. If dog A exerts a force of 270 N and dog B exerts a force of 300 N, find the magnitude of the resultant force and the angle it makes with dog A's rope. 4.57 CP Two boxes, A and B, are connected to each end of a light vertical rope, as shown in Fig. P4.57. A constant upward force F = 80.0 N is applied to box A. Starting from rest, box B descends 12.0 m in 4.00 s. The tension in the rope connecting the two boxes is 36.0 N. (a) What is the mass of box B? (b) What is the mass of box A? A B