# Heat Engine - Maximum Efficiency

## Homework Statement

A heat engine operates between a reservoir at 25 degrees Celsius and one at 375 degrees Celsius. What is the maximum efficiency possible for this engine?

## Homework Equations

e = $$\frac{Qc}{Qh}$$

## The Attempt at a Solution

I'm afraid that the equation above requires units in Joules to calculate thermal efficiency. Is there an equation adapted for this situation? Or does this require more figuring?

## Answers and Replies

Just a little more figuring ;) think of the Carnot cycle ;)

Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
Check your textbook for another efficiency equation, one involving absolute temperatures rather than Q's.

Andrew Mason
Science Advisor
Homework Helper

## Homework Statement

A heat engine operates between a reservoir at 25 degrees Celsius and one at 375 degrees Celsius. What is the maximum efficiency possible for this engine?

## Homework Equations

e = $$\frac{Qc}{Qh}$$
Efficiency is the ratio of Energy (work) out to Energy (heat flow) in. This is not Qc/Qh

AM