Question 380: Properties of Matter

Question

A slab of stone of area 0.36 m
2
and thickness 0.1 m is exposed on the lower surface to steam at 100
o
C. A block of ice at 0
o
C rests on the upper surface of the slab. In one hour 4.8 kg of ice is melted. The thermal conductivity of slab is
(Given latent heat of fusion of ice = 3.36 $$ 	imes $$ 10
5
J kg
$$-$$1
)

Accepted Answer

Rate of heat given by steam = Rate of heat taken by ice
where K = Thermal conductivity of the slab
m = Mass of the ice
L = Latent heat of melting/fusion
A = Area of the slab
$${{dQ} \over {dt}} = {{KA\left( {100 - 0} ight)} \over 1} = m{{dL} \over {dt}}$$,
$${{K 	imes 100 	imes 0.36} \over {0.1}} = {{4.8 	imes 3.36 	imes {{10}^5}} \over {60 	imes 60}}$$
K =1.24 J/m/s/ÃÂ°C

Answer

1.24 J/m/s/
o
C

Answer

1.29 J/m/s/
o
C

Answer

2.05 J/m/s/
o
C

Answer

1.02 J/m/s/
o
C

Properties of Matter

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