Skip to main content
J
jalvarez-21-Visitor
1-Visitor
March 16, 2017
Solved

Can someone help me?

  • March 16, 2017
  • 1 reply
  • 1371 views

Hi guys,

I keep getting an error on a formula, but the formula is just from one of my textbooks, so there isn't much I can change.

I am wondering why mathcad keep giving me this error.

See attachment

Best answer by MJG

The units are inconsistent in the equation.  It's physically impossible to add Length^-0.5, Length^-1, and Length^-2.

Your equation is likely empirical where L.tot is expected to be a certain unit.  Assuming that L.tot is expected to be in meters, and a.0 is supposed to be unitless, you can modify the equation like this:

which can also be re-written as:

If a.0 is expected to have units, just multiply the whole equation by those units.

1 reply

M
MJG1-VisitorAnswer
1-Visitor
March 16, 2017

The units are inconsistent in the equation.  It's physically impossible to add Length^-0.5, Length^-1, and Length^-2.

Your equation is likely empirical where L.tot is expected to be a certain unit.  Assuming that L.tot is expected to be in meters, and a.0 is supposed to be unitless, you can modify the equation like this:

which can also be re-written as:

If a.0 is expected to have units, just multiply the whole equation by those units.

Terms & ConditionsCookie settingsAccessibility statement