A 200-kg sample of Granite is heated to a temperature of 98°C and elongates by 25mm. If its
temperature before it is heated is 25°C, specific heat is 0.80 J/g-K and its length extends to
250mm, calculate the following:
a. Heat absorbed or thermal conductivity
b. Linear expansion coefficient
a. Heat absorbed or thermal conductivity
K = (QL)/(AΔT), Where;
K is the thermal conductivity in W/m.K.
Q is the amount of heat transferred through the material in Joules/second or Watts.
L is the distance between the two isothermal planes.
A is the area of the surface in square meters.
ΔT is the difference in temperature in Kelvin.
K= (0.80 J/g-K*225mm)/73
K= 2.4658
b. Linear expansion coefficient
ΔL = αLΔT, Where;
ΔL is the change in length L,
ΔT is the change in temperature, and
α is the coefficient of linear expansion, which varies slightly with temperature.
α=ΔL/ΔT
α=(250mm-25mm)/(98°C-25°C)
α= 225mm/73°C
α=3.0822
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