Question
How many watts does a flashlight that has $6.00 \times 10^2 \textrm{ C}$ pass through it in 0.500 h use if its voltage is 3.00 V?

$1.00 \textrm{ W}$

Solution Video

# OpenStax College Physics Solution, Chapter 20, Problem 43 (Problems & Exercises) (0:33)

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Video Transcript

This is College Physics Answers with Shaun Dychko. To find the power in Watts used by the flashlight, we’re going to multiply the current by the voltage. But we’re given the current in a roundabout way by being told how many Coulombs go through the flashlight in how much time, and so we have six times ten to the two Coulombs passing through in half of an hour which we convert into seconds by multiplying by 3600 seconds per hour, and then multiply all this by three Volts, this gives 1.00 Watts.