Question

く) 70111 Part A How much heat is exhausted to the cold reservoir by the heat engine shown in the figure? Assume that Q 10o J and Q, 250 Figure 1) Express your answer to two significant figures and include the appropriate units. QcValue Units gure 1 of 1 xt > P kPa) Provide Feedback 0, 200- Q, V(cm) 0 300 600 888 a 9

Answer 1

Work done by the engine in a cyclic process is the area enclosed by a loop of the cycle.

W = area of triangle

W = (1/2) (600 -300 )(300 - 100)

W = 3 X 10⁴ Kpa cm³

W = 3 X 10⁴ X 1000 X 10^-6 Pam³

W = 30 J

Total heat supplied Q = Q₁ + Q₂

Q = 100 +250

Q = 350 J

For a cyclic process gas is at the same state after each cylce so the change in internal enery after each cycle is zero.

$\Delta U = U_{f} - U_{i} = 0$

Applying first law of thermodynamics

$\Delta Q = \Delta U + \Delta W$

$\Delta Q = 0+ 30$

$\Delta Q = 30$

$Q_{i} - Q_{o }= 30$

350 - Q_o = 30

Q_o = 350-30 = 320 J

The heat exhausted to cold reservoir is 320J