Converting Watts to Volts: Maximum Current for a 3.5W Resistor

[haleyscavone]

What is the maximum current allowed in a 3.5 W, 220 ohm resistor?

The answer needs to be in amps so how would I convert watts to volts?

 

[mgb_phys]

Whats the formula for power dissapation in a resistor?
hint, V=IR and P=IV

 

[haleyscavone]

Because the voltage was unknown you would use both equations and substitution right?
So P=I(IR) ---> P=I^2R

So 3.5/220=I^2
.0159=I^2
I=.1581

Is that correct?

 

[mgb_phys]

Slight typo/mistake in your sqrt but yes - that's the correct method

 

[haleyscavone]

thank you!