Problem A13: A plank of length 100 cm has a box on top of it. The box has a weight of 50 Newtons. The plank (plus box) are held up by two vertical...

Problem A13: A plank of length 100 cm has a box on top of it. The box has a weight of 50 Newtons. The plank (plus box) are held up by two vertical forces located at each end of the plank. The force on the left is n1 Newtons, and the force on the right is n2 Newtons. Everything is in static equilibrium. If the box is located a distance of n3 cm from the left end, what is n3? Note that the plank is of uniform density and does have weight.