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An engine does 62 J of work each cycle as it absorbs 2 times as much heat as it discharges to the environment. A) Determine the efficiency of the engine in percent. B) What quantity of heat is discharged to the environment each cycle in Joules?

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Answer:

A) 150%

B) 20.67 J

Explanation:

A) To determine the efficiency of the engine, we can use the formula:

efficiency = (work output / heat input) x 100%

In this case, the engine does 62 J of work each cycle, so the work output is 62 J. We're also given that the engine absorbs 2 times as much heat as it discharges to the environment, so we can express the heat input as 2 times the heat discharged:

heat input = 2 x heat discharged

Therefore, we can rewrite the efficiency formula as:

efficiency = (62 J / (2 x heat discharged)) x 100%

Simplifying this expression, we get:

efficiency = 31 J / heat discharged

Now we need to determine the value of heat discharged. We know that the engine absorbs 2 times as much heat as it discharges, so the net heat input is 3 times the heat discharged:

net heat input = heat input - heat discharged = 2 x heat discharged - heat discharged = heat discharged

Therefore, we can express the net heat input as:

net heat input = 3 x heat discharged

Now we can use the first law of thermodynamics, which states that the net heat input is equal to the work output plus the heat discharged:

net heat input = work output + heat discharged

Substituting the given values, we get:

3 x heat discharged = 62 J + heat discharged

Solving for heat discharged, we get:

heat discharged = 20.67 J

Now we can calculate the efficiency:

efficiency = 31 J / 20.67 J = 1.50 or 150%

Therefore, the efficiency of the engine is 150%.

B) To determine the quantity of heat discharged to the environment each cycle in Joules, we can use the value we calculated above for heat discharged:

heat discharged = 20.67 J

Therefore, the quantity of heat discharged to the environment each cycle is 20.67 J.

Hope this helps!

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