SOLUTION: Hi, This is pretty basic, but I have forgotten my algebra. I wish to substitute in ohm's law formulae to find soultions for power. given. E=IR and P=EI In an electrical circu

Algebra ->  Equations -> SOLUTION: Hi, This is pretty basic, but I have forgotten my algebra. I wish to substitute in ohm's law formulae to find soultions for power. given. E=IR and P=EI In an electrical circu      Log On


   

Question 490930: Hi,
This is pretty basic, but I have forgotten my algebra.
I wish to substitute in ohm's law formulae to find soultions for power.
given. E=IR and P=EI
In an electrical circuit only P and R are known. Solve for E and Solve for I.
I know the answers are E=√PR and I=√P/R but I don't remember how to solve for them.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
given. E=IR and P=EI
In an electrical circuit only P and R are known. Solve for E and Solve for I.
:
E = I*R
R = E%2FI
I = E%2FR
:
solving for E using P & R
EI = P
E = P%2FI
Replace I with (E/R)
E = P%2F%28E%2FR%29
which is
E = %28PR%29%2FE
multiply both sides by E
E^2 = PR
Find the square root of both sides
E = sqrt%28PR%29
:
Solving for I using P & R
EI = P
I = P%2FE
Replace E with IR
I = P%2F%28IR%29
multiply both sides by I
I^2 = P%2FR
Find the square root of both sides
I = sqrt%28P%2FR%29
: