How do I find the current if the problem only gives me resistance and power?

Question

joannablackwelder · Answer

P=IV and V=IR so P=I(IR)

joannablackwelder · Answer

Thus I=sqrt(P/R)

anonymous · Answer

So an example being, A device has a resistance of 67 ohms and a Power rating of 43 watts what is the current? How would you do this?

anonymous · Answer

I am still confused about how you got to that formula.

joannablackwelder · Answer

Are you familiar with the two formluas I mentioned before substituting?

anonymous · Answer

Yes

joannablackwelder · Answer

43 W=I^2 * 67 ohms, solve for I.

joannablackwelder · Answer

Using dimensional analysis, I get the unit of A.

anonymous · Answer

You are going wayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy beyond the 9th grade level with vocab.

joannablackwelder · Answer

Do you mean dimensional analysis? That is just ignoring the numbers and looking only at the units.

anonymous · Answer

OH. I am so stupid. o. o

anonymous · Answer

What is the unit "A"

joannablackwelder · Answer

No worries. A is the unit of current.

anonymous · Answer

Power consumed by 
heating = P = I^2 R = current squared times resistance

so 

I = sqrt(P/R),  as noted by J-B-.