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 NEED Help From Basic Ohm's Law to E=SqRt of P*R 
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Post NEED Help From Basic Ohm's Law to E=SqRt of P*R
Basic Ohm's Law E P
----------------
----------------
I R E I

What simple Ohm's Law formulas get combined to (Exp.E=RxI E=P/I} to
arrive at I=SqRt of P/R V=SqRt of P*R P= V^2/R

Thank You for any advice Frustrated Apprentice


17 Mar 2008, 15:50
Post Re: NEED Help From Basic Ohm's Law to E=SqRt of P*R
"rdelec"

> What simple Ohm's Law formulas get combined to (Exp.E=RxI E=P/I} to
> arrive at I=SqRt of P/R V=SqRt of P*R P= V^2/R

** P = VI

Substituting V/R for I, gives P = Vsquared / R
-------------------------

V = P / I

Substituting V/R for I, gives V = P * R /V

So V squared = P*R

------------------------

I = P / V

Substituting I*R for V, gives I = P /I*R

So, Isquared = P/R



...... Phil


17 Mar 2008, 15:50
Post Re: NEED Help From Basic Ohm's Law to E=SqRt of P*R
rdelec wrote:
> Basic Ohm's Law E P
> ----------------
> ----------------
> I R E I
>
> What simple Ohm's Law formulas get combined to (Exp.E=RxI E=P/I} to
> arrive at I=SqRt of P/R V=SqRt of P*R P= V^2/R
>
> Thank You for any advice Frustrated Apprentice

I can't read your formulas so well, so I will repeat them.

E=I*R P=E*I

If substitute the first expression that equals E for the E
in the second formula, you get P=(I*R)*I=I*I*R=(I^2)*R.

If you take the square root of both sides of P=(I^2)*R you
get sqrt(P)=I*sqrt(R). Then dividing both sides by the
sqrt(R) you get sqrt(P)/sqrt(R)=sqrt(P/R)=I.

If you rearrange the first to solve for I by dividing both
sides by R, you get E/R=I. Then you can substitute this
equivalent of I for the I in the power formula.
P=E*(E/R)=E*E/R=(E^2)/R.

If you take the square root of both sides of P=(E^2)/R, you
get sqrt(P)=E/sqrt(R). Multiplying both sides by sqrt(R)
you get sqrt(P)*sqrt(R)=sqrt(P*R)=E.

Is that what you needed?
--
Regards,

John Popelish


17 Mar 2008, 15:51
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