A 100-W light bulb is left on for 20.0 hours.Over this period of time,how much energy did the bulb use?
A) 1000 J
B) 7.2 MJ
C) 3,600,000 J
D) 1.34 hp

Question

Quizplus · Accepted Answer

The energy used by the bulb can be calculated using the formula: Energy (in joules) = Power (in watts) × Time (in seconds). Converting 20 hours to seconds (20 × 3600 = 72,000 seconds), the energy used is 100 W × 72,000 s = 7,200,000 J, which is 7.2 MJ.

A 100-W Light Bulb Is Left on for 20