2. A girl and a boy pulled horizontally on ropes attached to a 20 kg box and made it to slide over a concrete surface (ur=0.8). The angle between two ropes is 90 a. Sketch a the free-body diagram where forces exerted by both the girl and the boy are equal. b. Solve for the kinetic friction exerted by the surface on the box. c. Solve for the forces exerted by both the girl and the boy when the box des at constant velocity. d. Solve for the net force acted on the box, and its acceleration, if the boy and the girl both applied 300 N force to the box. . Identify at least 5 action-reaction pairs that you may think possible in this problem​