Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.

Free-body diagrams and kinematics

Bob is pushing box of mass 100 kg with a constant force F; however, his force isn't purely horizontal, but exerted at an angle of 10 degrees below the horizontal. The sticky floor exerts a frictional force of 400 N to the left, but the box does slide across the floor. Starting from rest, it moves 10 meters in 5 seconds.

  1. What is the force F with which Bob pushes the box?
  2. What is the normal force of the floor on the box?

Fill in these tables to help yourself solve the problem.

   force        x            y
  --------------------------------
           |          |         
           |          |         
           |          |         
           |          |         
           |          |         
           |          |         
           |          |         
           |          |         
  --------------------------------
   total   |          |
  --------------------------------


                x           y
  --------------------------------
   accel   |          |
           |          |
  --------------------------------
  

Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.