Question

A load of bricks is lifted to the second floor of a building. How do work and power relate to this job?

The longer the job takes, the more work is done.
The faster the job is done, the greater the power.
The greater the power applied, the more work is done.
The less work is done, the more power is needed.

Answer 1

Correct evaluation:

1. False. The work to lift the bricks = m g h (or W = F · d) and does not depend on how long it takes.
2. True. Power = work / time (P = W/t), so doing the same work in less time requires greater power.
3. False (as stated). Power is the rate of doing work; a larger power only means work is done faster. It does not necessarily mean more total work is done (unless applied for the same longer time).
4. False. Less work does not imply more required power; for a given time less work means less power.

Short summary: Work depends on force and displacement (mgh for lifting), power is the rate at which that work is done (W/t).