Practice Power in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The rate at which work is done or energy is transferred, measured in watts (joules per second).
How fast you use or produce energy. A powerful engine does work quickly.
Example 1
easyA motor does 6000 \text{ J} of work in 30 \text{ s}. What is the power output?
Example 2
mediumA 70 \text{ kg} person runs up a 5 \text{ m} staircase in 4 \text{ s}. What is the power output? Use g = 9.8 \text{ m/s}^2.
Example 3
easyA 100 \text{ W} light bulb is on for 2 \text{ hours}. How much energy does it use?
Example 4
mediumTwo cranes each lift a 500 \text{ kg} load 20 \text{ m}. Crane A takes 50 \text{ s} and Crane B takes 100 \text{ s}. What is each crane's power output? Use g = 10 \text{ m/s}^2.