Lesson: Power and Energy Physics • 9th Grade

In this lesson, we will learn how to use the formula P = E/t to calculate the rate at which energy is transferred by a device given the amount of energy it transfers in a given time.

Lesson Plan

Students will be able to

give a definition of power in terms of energy and time,
use in all permutations,
apply to electric circuits and appliances.

Lesson Video

Lesson Playlist

04:43
03:55

Lesson Worksheet

Q1:

A 24 W fluorescent light is left on for several hours, during which time it is supplied with 432 kJ of energy. For how many hours was the light left on?

Q2:

Which of the following is the correct unit for power?

Q3:

A 250 W television and a 400 W television are both used for two hours. How much more energy does the 400 W television require to operate for this time than the 250 W television?