Question

An elevator of mass m is initially at rest on the first floor of a building. It moves upward, and passes the second and third floors with a constant velocity, and finally stops at the fourth floor. The distance between adjacent floors is h. What is the net work done on the elevator during the entire trip, from the first floor to the fourth floor?

1. W = ?4 m g h
2. None of these.
3. W = 0
4. W = 4 m g h
5. W = ?3 m g h
6. W = 3 m g h

Answer 1

W = 0

Step-by-step explanation:

The formula for Work is Force multiplied by distance. For there to be a force, there must be acceleration. In this case, the elevator has a constant velocity, and so the acceleration is 0. If the acceleration is zero, the force is zero, and so the work is zero.