Economics for Engineers
Efficiency and Profit Margins
By Administrator
First published on April 17, 2021. Last updated on April 17, 2021.
Gross Margin
Let’s again consider a heat engine operating across a thermal conductor.
In business, the Gross Profit Margin, or simply Gross Margin (MG), can be expressed as:
\(GM = \frac{R – C}{R}\).
The form of this equation may look familiar. It is identical in form to the expression for Carnot efficiency:
\(\epsilon = \frac{T_H – T_C}{T_C} =1 – \frac{T_C}{T_H}\)
So we can now express Gross Margin thermodynamically:
\(GM = \epsilon = 1 – \frac{T_C}{T_H}\)
We can now express Marginal Profit thermodynamically:
\(P =Q_H~\epsilon = Q_H~(1 -\frac{T_C}{T_H})\)
In Summary, the work performed by the heat engine represents profit (P):
\(W = Q_H (1 – \frac{T_C}{ T_H})\)