When a certain ideal engine performs 2000 kj of work, 4750 kj of heat flows out of the engine at 275°c. (a) how much heat flows into the engine? (b) what is the efficiency of the engine? (c) at what temperature does heat flow into the engine?

a) Qh= 6750 kJ

b) e = 0.296

c) = 390.625° C

Explanation:

Given:

Work done, W = 2000 kJ

Heat flow, Q = 4750 kJ

Temperature at which heat flows out, = 275° C

a) Now, the heat flow through the engine (Qh)

Qh = W + Q

or

Qh = 2000 + 4750

or

Qh= 6750 kJ

b) The efficiency (e) is given as:

on substituting the values, we get

or

e = 0.296

c)

where,

is the temperature at which heat flow

on substituting the values, we get

or

= 390.625° C