Question

What volume of water at 0 ∘C can a freezer make into ice cubes in 1.5 h , if the coefficient of performance of the cooling unit is 9.0 and the power input is 1.2 kilowatt? Express your answer using two significant figures.

Answer 1

Answer:

$1.7\times 10^{-1}\ m^3$

Explanation:

$\rho$ = Density of water = 1000 kg/m³

Mass is given by

$m=\rho V\\\Rightarrow m=1000V$

$Q=mL\\\Rightarrow Q=1000V336000\\\Rightarrow Q=336\times 10^{6}V$

Energy used is

$9\times 1200=10800\ W$

$Q=10800\times 1.5\times 3600=58320000\ J$

$336\times 10^{6}V=58320000\\\Rightarrow V=\dfrac{58320000}{336\times 10^{6}}\\\Rightarrow V=0.173571428571\ m^3$

The volume of water is $1.7\times 10^{-1}\ m^3$