How Do I Determine the Thermal Conductivity of Glass from My Graph?

AI Thread Summary
To determine the thermal conductivity of glass from the provided graph, it's essential to correctly interpret the plotted values of lg temperature against time. The slope of the graph relates to the thermal conductivity, which is calculated using the formula k/Brx, where k, b, r, and x are constants. The initial temperature of 20°C complicates the calculation, as it does not yield a clear intercept on the graph. It's crucial to ensure that all units are consistent, specifically in watts per meter per Kelvin (W m^(-1) K^(-1)). Accurate unit management and a careful review of the slope will lead to the correct thermal conductivity value.
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Hi there,...this isn't homework..its more to my practical...anyways...from the attachment given..that is the first page of my practical guide...the problem is...on the procedure part...it asked me to plot a graph of lg temp againts t ...if i do so...how do i get the thermal conductivity of glass as the initial temp is 20 C ?!?...so weird...because i don't get lg 20 as interception from the graph...btw..if i simply assume the gradient of graph plotted is kt/Brx ...then my thermal conductivity of glass is 0.2++...i don't think that's right :(...help me anyone..please

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First of all
thermal conductivity of glass is 0.2++...

What is the unit. IT all depends on the units.
 
I think you need to look at the slope value again. It should be k/Brx since t is your independent variable and k,b,r and x are all constants. Also, pay heed to Gamma. Units will be your downfall if you are not careful.
 
oh..the units are all in W m^(-1) K^(-1)
 
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