A slab of stone of area 0.36 m2 and thickness 0.1 m is exposed on the ...
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
K =1.24 J/m/s/°C
View all questions of this test
A slab of stone of area 0.36 m2 and thickness 0.1 m is exposed on the ...
°C. The upper surface is exposed to air at 25°C. The thermal conductivity of the stone is 2.5 W/mK. The density of the stone is 2500 kg/m3 and its specific heat capacity is 800 J/kgK.
We can use the following equation to calculate the rate of heat transfer through the slab:
Q/t = kA(T1 - T2)/L
where Q/t is the rate of heat transfer (in watts), k is the thermal conductivity (in watts per meter Kelvin), A is the area of the slab (in square meters), T1 is the temperature of the steam (in Kelvin), T2 is the temperature of the air (in Kelvin), and L is the thickness of the slab (in meters).
Plugging in the given values, we get:
Q/t = (2.5 W/mK)(0.36 m2)((100 + 273) K - (25 + 273) K)/(0.1 m) = 738 W
This means that 738 joules of heat are transferred through the slab every second.
To calculate the temperature of the slab at any given time, we need to use the following equation:
Q = mcΔT
where Q is the amount of heat transferred (in joules), m is the mass of the slab (in kilograms), c is the specific heat capacity of the stone (in joules per kilogram Kelvin), and ΔT is the change in temperature (in Kelvin).
We can rearrange this equation to solve for ΔT:
ΔT = Q/(mc)
Plugging in the given values, we get:
ΔT = 738 J/(2500 kg)(800 J/kgK) = 0.37 K
This means that the temperature of the slab will increase by 0.37 Kelvin every second. After a certain amount of time, the temperature of the slab will reach an equilibrium point where the rate of heat transfer into the slab equals the rate of heat transfer out of the slab. At this point, the temperature of the slab will be constant.