A2L Item 146

Goal: Hone the concept of potential energy functions

Source: UMPERG-ctqpe65

The
potential energy function for a certain body is shown at right. If the
body is released from rest at a location corresponding to point 4, the
object would …

  1. move towards larger values of x.
  2. move towards smaller values of x.
  3. remain stationary.
  4. oscillate back and forth.
  5. None of the above
  6. Cannot be determined

Commentary:

Answer

(2) At position 4 the object experiences a force toward the
origin given by the negative of the slope of the potential curve.
Frequently students interpret the fact that U is zero at point 4 to mean
that there is no force.