AP PROBLEM

SLIDING BOX, ROPE AND FRICTION

A box of uniform density weighing 100 newtons moves in a straight line with constant speed along a horizontal surface. The coefficient of sliding friction is 0.4 and a rope exerts a force F in the direction of motion as shown above.

A) Make a diagram, draw and identify all the forces on the box.

B) Calculate the force F exerted by the rope that keeps the box moving with constant speed.

C) A horizontal force F', applied at a height 5/3 meters above the surface as shown in the diagram, is just sufficient to cause the box to begin to tip forward about an axis through point P. The box is 1 meter wide and 2 meters high. Calculate force F'.