how do i do this physicsproblem?
If the energy removed from an engine as heat
during one cycle is 5.0 × 102 J, how much
energy must be added to the engine during
one cycle in order for it to operate at 28
percent efficiency?
Answer in units of J.
If the energy removed from an engine as heat
during one cycle is 5.0 × 102 J, how much
energy must be added to the engine during
one cycle in order for it to operate at 28
percent efficiency?
Answer in units of J.
Comments
As the efficiency is 28%=>the wastage is (100 - 28 = 72%)
=>Let the energy required to operate is M Jules/cycle
=>M x 78% = 5 x 10^2 J
=>M = 5 x 10^2 x 100/78 = 6.4 x 10^2 J/cycle
Here we have,
Heat energy = 5.0 x 102 J
efficiency = 28 %
Let Total Energy = E,
Then
5.0 x 102 x 100 / E = 28
E = 5.0 x 102 x 100 / 28 = 1821.43 J .................. Answer
-Number of loops x (Change in magnetic flux/change in time) x 100= percent efficency of engine