Physics 101- Introduction to Mechanics
March 11- Work- Kinetic Energy Theorem






  Gravitational Work

You want to load a box into the back of a truck.  One way is to lift it straight up through a height h, doing work W1.  Alternatively, you can slide the box up a loading ramp a distance L, doing work W2.  Assuming that the box slides on the ramp without friction which of the following is correct W1 < W2, W1 = W2, or W1 > W2?

When working on problems & exercises using energy, follow the hints/ algorithm found on page 109.

  1. Identify the body whose motion is to be analyzed (define the system)
  2. Choose an inertial reference frame.
  3. Identify the path over which the work-energy theorem is to be applied. (determine the initial and final states)
  4. Determine what forces are acting on the body (draw a FBD)
  5. Calculate the work done over the path by every force
  6. Equate the net work done on the body over the path to the change in kinetic energy of the body between the initial and final points of the path.


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Jeff Phillips
Loyola Marymount University
Spring 2002