Please help me understand the correct answer for these, please do not guess. ___
ID: 1883870 • Letter: P
Question
Please help me understand the correct answer for these, please do not guess.
_________ is the exchange of mechanical energy across a boundary.
heat
work
force
none of the above
________________________________________________________
An output power needed from an electric motor is 50 hp. If the motor has some inefficiency, what would be an expected input power.
48 hp
50 hp
52 hp
________________________________________________________
The theoretical maximum efficiency for a heat engine _______.
is 100%
is always less than 100%
not enough information
heat
work
force
none of the above
________________________________________________________
An output power needed from an electric motor is 50 hp. If the motor has some inefficiency, what would be an expected input power.
48 hp
50 hp
52 hp
________________________________________________________
The theoretical maximum efficiency for a heat engine _______.
is 100%
is always less than 100%
not enough information
Explanation / Answer
In Thermodynamic systems the HEAT is the exchange of mechanical energy across a boundary.
from first law of thermodynamics
dQ = dU + dW
answer is HEAT
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givne out put power of the motor is 50 hp
the motor has some inefficiency so the input power must be greater than output
that is from the options 52 hp is the appropriate answer
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The theoritical maximum efficiency of a heat engine(Carnot engine) is 100% which is ideal case only.