# Converting a value material parameter

## Homework Statement

I have E as a material parameter. It is a modulus of Elasticity It is given as:
109/E = 80/psi

I want to write E as a value with units psi.

## The Attempt at a Solution

Is this correct?

1/E = 80*109/psi
So
psi/E = 80*109
So
E = 1.25*10^7 psi

Mark44
Mentor
Mentor note: Thread moved from Calculus section

## Homework Statement

I have E as a material parameter. It is a modulus of Elasticity It is given as:
109/E = 80/psi

I want to write E as a value with units psi.

## The Attempt at a Solution

Is this correct?

1/E = 80*109/psi
So
psi/E = 80*109
So
E = 1.25*10^7 psi
Looks fine to me, although your problem description omits some information. Apparently you're converting from some kind of units to PSI. Since you're converting between two kinds of units, you should include the unit you're converting from, not just the one you're converting to.
Your equation looks weird with "psi" ujits on one side, and no units shown on the left side.

A quicker way than you found is this:
If ##\frac {10^9} E = \frac {80}{\text{psi}}##
then ##\frac E {10^9} = \frac{\text{psi}} {80}## -- if two fractions are equal, then their reciprocals are also equal (providing neither fraction is 0)
Now multiply both sides by ##10^9## and simplify a bit.