Propeller torque & engine torque

[Capt Pit Bull]

Sorry I'm late.

Italia is correct (give or take the odd minor slip / assumed simplification e.g. zero wind etc).

Oggers, you don't understand efficiency.

An engine in a test bed does NOTHING except churn up air thereby producing heat. If the object an engine is attached to does not increase in the total of GPE +KE as a result of the efforts of the engine then no *useful* work is being done. Likewise a person straining on a wrench is just producing heat. In both cases energy is certainly used, but not usefully.

This is my one and only post on the topic. Oggers, you have a long ingrained 'alternative framework'. Unless you are at least prepared to consider that something you think you understand could be wrong I, like italia, see no point in spending any time over it.

pb