Work output and thermal efficiency of an aircraft engine

[jchipwpunj]

Homework Statement

An aircraft engine akes in 9000 Joules of heat and discards 6400 J each cycles a) What is the mechanical work output of the engine during one cycle? b) What is the thermal efficiency of the engine?

Homework Equations

e=W/Qh

The Attempt at a Solution

A)
Qh = 9000 J
Qh - WORK = WORKwasted
9000 J - 6400 J = W = 2600 J

B)
e = WORK / Qh
e = 2600 J / 9000 J = .2888 * 100% = 28.9%

 

[Redbelly98]

Looks good!