Answer:
A. Q = 2.74 x 10⁷ J = 27.4 MJ
B. E = 3.91 x 10⁸ J = 391 MJ
Explanation:
A.
Heat rejected can be found as follows:
[tex]Q = mL[/tex]
where,
Q = Heat rejected = ?
m = mass = 82.1 kg
L = Latent Heat of fusion = 334000 J/kg
Therefore,
[tex]Q = (82.1\ kg)(334000\ J/kg)[/tex]
Q = 2.74 x 10⁷ J = 27.4 MJ
B.
First, we will calculate the efficiency of the Carnot Cycle as follows:
[tex]Efficiency = 1-\frac{T_1}{T_2}[/tex]
where,
T₁ = Heat intake temperature = 0°C + 273 = 273 k
T₂ = Heat rejection temperature = 20.6°C + 273 = 293.6 k
Therefore,
[tex]Efficiency = 1 - \frac{273\ k}{293.6\ k} \\\\Effciency = 0.07[/tex]
Therefore, the energy input required is:
[tex]Efficiency = \frac{Q}{E}\\\\E = \frac{Q}{Efficiency} = \frac{2.74\ x\ 10^7\ J}{0.07}[/tex]
E = 3.91 x 10⁸ J = 391 MJ
