Problem 3.2

Set the acceleration of the elevator to: a = m/s2

Please wait for the animation to completely load.

A 50-kg box is riding in an elevator that accelerates downward at a constant rate (position is given in meters and time is given in seconds). (Its velocity vector is shown in green.) The box rests on a digital scale that records its apparent weight in Newtons. The green arrow represents the instantaneous velocity of the elevator.  Adjust the value of the acceleration (-9.8 m/s2 ≤ a ≤ 9.8 m/s2) and see how it affects the apparent weight.   Restart.

  1. Draw a free-body diagram for the box.
  2. What force is recorded on the scale?
  3. Apply Newton's 2nd Law to the box's motion, and determine the value of its acceleration that would make that force vanish. In other words, how can the box become apparently "weightless"?