Question

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 5.90×10−2 kg . Throughout this problem use Lf=3.34×105J/kg for the heat of fusion for water. Part A During this time, how much work W is performed by the engin

Answer 1

Answer:

W = 7.214 k J

Explanation:

given,

time of operation = 5 minutes

mass of ice melt = 5.90 × 10⁻² kg

L_f = 3.34 × 10⁵ J/kg

Work done = ?

We know work done

     $|W| = |Q_h| - |Q_c|$

$Q_c = - m L_f$

$Q_c= - 5.90\times 10^{-2}\times 3.34 \times 10^5$

$Q_c = -19.706 kJ$

$Q_h = Q_c \dfrac{T_H}{T_C}$

T_H is the heat from hot reservoir = 373 K

T_C is the energy released to cold reservoir = 273 K

$Q_h = -19.706\times \dfrac{373}{273}$

$Q_h =-26.92 kJ$

now,

     $|W| = |-26.92| - |-19.706|$

              W = 7.214 k J