A heat engine has taken in energy as heat and used a portion of it to do work. What must happen next for the engine to complete the cycle and return to its initial conditions?
a. It must give up energy as heat to a lower temperature so work can be done on it.
b. It must give up energy as heat to a higher temperature so work can be done on it.
c. It must do work to transfer the remaining energy as heat to a lower temperature.
d. It must do work to transfer the remaining energy as heat to a higher temperature.
2007-12-07 00:13:02 · 2 answers · asked by thisisjakethomas 1 in Science & Mathematics ➔ Engineering
a,
Obviously one couldn't very well give up heat to a higher temperature, and it doesn't really require the engine to do any work to transfer energy to a lower temperature, it will go there on it's own.
In practice, many engines do some work to push hot gases out of the engine, but for a theoretical engine I'd pick (a) rather than (c)
2007-12-07 02:08:03 · answer #1 · answered by tinkertailorcandlestickmaker 7 · 0⤊ 0⤋
C. Since only part of the heat has been used,
the rest must be somehow expended to return
to the original condition.
2007-12-07 14:30:54 · answer #2 · answered by Irv S 7 · 0⤊ 0⤋