1. Section 1 (cont.)
Power

2. I. Power
A. The rate at which work is done.

3. B. Power is measured in Watts (W).
Examples:
A medium-sized car engine is rated at 50,000 to 100,000 Watts
A person who weighs 220 pounds climbing a foot high ladder in 5 seconds is doing work at a rate of about 600 Watts

4. It takes 100,000 J of work to lift an elevator 18 meters
It takes 100,000 J of work to lift an elevator 18 meters. If this is done in 20 seconds, what is the average power of the elevator during this time?
GIVEN:
WORK:
W = 100,000 J
t = 20 s
P = ?
work
time
P = P W t
100,000 J
20 s
P =
P = 5,000 W