Power, Voltage and Current - Hairdryer Problem

AI Thread Summary
A household circuit can carry a maximum of 30.0 A at 120 V, equating to a total power capacity of 3600 W. Given that each hair dryer uses 1500 W, the calculation shows that 3600 W divided by 1500 W equals 2.4 hair dryers. However, since hair dryers must be counted in whole numbers, only 2 hair dryers can operate simultaneously on this circuit. The confusion arose from misinterpreting the instruction about integer units, as fractional hair dryers are not feasible. Therefore, the correct answer is that only 2 hair dryers can run off one circuit.
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Homework Statement


A typical household circuit is capable of carrying 30.0 A of current at 120 V before the circuit breaker will trip. How many 1500-W hair dryers can run off one such circuit?

Use the relation between power, current and voltage. Also, remember hair dryers come in integer units.

Homework Equations


P = VI


The Attempt at a Solution


P = 120 * 30 = 3600
3600/1500 = 2.4

This is incorrect and I don't understand why. Am I missing something?
 
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What's 0.4 of a hairdryer?
 
Ah, thank you. I only put 2.4 because they said "Also, remember hair dryers come in integer units" so I thought they wanted the .4.

Thank you!
 

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