Power

What this chapter teaches

Power is the rate of transferring energy, in watts, where one watt is one joule each second. Time must be in seconds and power in watts before the sums are done. A person climbing stairs can find their own power from their mass, the height and the time.

Three questions to ask

There is no one right wording. Listen for the idea.

1. What is the difference between a joule and a watt?
2. How would you find the power of someone climbing the stairs?
3. A 10 W lamp is on for an hour and a 100 W lamp for a minute. Which one transfers more energy?

After the chapter, the learner can

• Calculate power in watts from energy and time
• Measure your own power by timing yourself climbing stairs