2006-09-12 18:36:40 · 10 answers · asked by mahesh k 2 in Science & Mathematics ➔ Physics
No. There is always heat loss through radiation.
Doug
2006-09-12 18:39:07 · answer #1 · answered by doug_donaghue 7 · 0⤊ 0⤋
An engine, such as a car engine (internal combustion), steam engine, or turbine operates by extracting mechanical work from heat. To work, the engine needs a heat source (usually fuel and air) and a place to dump the waste heat such as cooling towers for a nuclear plant or the exhaust of a car engine.
The engine must be able to reject this heat to the environment or it cannot operate. The answer then is that an engine cannot work without an environment to dump waste heat into.
On another note, a heat engine, like the ones discussed here, do have a maximum efficiency called the Carnot efficiency. It is determined by the high and low temperatures in the engine. For most engines, this is less than 50%,
2006-09-13 01:52:44 · answer #2 · answered by Pretzels 5 · 1⤊ 0⤋
If you removed all of the surroundings of an engine (impossible) and attach to the cold side of the engine an infinite heat mass (also impossible) that was at absolute zero (probably impossible) and made your engine out of a material that had zero heat conductance (in order to keep the hot side from heating up the cold side at absolute zero -- you guessed it -- also impossible) and eliminated any friction inside the engine (this is getting redundant) then yes it would run at 100% efficiency.
A violation of any of those would prevent it from being 100% efficient. Bummer, huh. The 2nd law of thermodynamics is a you-know-what.
2006-09-13 01:52:13 · answer #3 · answered by selket 3 · 1⤊ 0⤋
you give energy that is transformed to work, lost in heat (entropy chanced will not be discussed etc..) and converted to a mechanical output. if no heat was lost and then an adiabatic system would be present.
either way if perfect circustance were to be performed at the end of the day your last "energy product" would still be less than 100% due to friction and convertion procedures.
if you are interested in how to avhieve maximum results from an engine (i hope it is an internal combustion engine) it is worth looking up that when it is cold outside you get a better result due to easier heat trenfer from the sytem to the surroundings.and realize what temperatures have to do with it.
in my mind (not valid of course) without the surroundings there would not be anywhere to "dispose the heat" therefore an increase in the entropy of the system would be present that is not desired either.
2006-09-13 01:57:53 · answer #4 · answered by Emmanuel P 3 · 0⤊ 0⤋
Perhaps...but if the surroundings were made absent then neither the engine nor the one operating/starting it would be able to know.
Does a falling tree make noise if no one can hear it?
2006-09-13 01:43:03 · answer #5 · answered by Capt 5 · 1⤊ 0⤋
With the surroundings removed, what good would your engine be?
2006-09-13 01:43:28 · answer #6 · answered by Helmut 7 · 0⤊ 0⤋
No. There has to be a heat sink, a place at 0 degrees celcius. I don't think that vacumn has a temperature assosciated with it.
2006-09-13 13:41:55 · answer #7 · answered by Sarab s 3 · 0⤊ 0⤋
The surroundings do not matter, what matters is the energy that escapes, what you need is a perfect isolation.
2006-09-13 02:56:27 · answer #8 · answered by luisof 1 · 0⤊ 0⤋
No. First law of thermodynamics is always in play, despite a closed system.
2006-09-13 01:54:58 · answer #9 · answered by MrZ 6 · 0⤊ 1⤋
I think no
2006-09-13 01:44:28 · answer #10 · answered by jvbaker06 1 · 0⤊ 0⤋