An engineer claims to have made an engine delivering $10 kW$ power with fuel consumption of $1 g/sec$. The calorific value of the fuel is $2 kcal/g$. Is the claim of the engineer
Medium
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(b) Input energy $ = \frac{{1g}}{{\sec }} \times \frac{{2kcal}}{g} = 2kcal/\sec .$
Output energy $ = 10\;KW = 10\;K\;J/S$$ = \frac{{10}}{{4.2}}kcal/\sec .$
==> $\eta = \frac{{{\rm{output}}\;{\rm{energy}}}}{{{\rm{input}}\;{\rm{energy}}}} = \frac{{10}}{{4.2 \times 2}} > 1,$ it is impossible.
Output energy $ = 10\;KW = 10\;K\;J/S$$ = \frac{{10}}{{4.2}}kcal/\sec .$
==> $\eta = \frac{{{\rm{output}}\;{\rm{energy}}}}{{{\rm{input}}\;{\rm{energy}}}} = \frac{{10}}{{4.2 \times 2}} > 1,$ it is impossible.
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