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In a cylindrical pipe where area isn’t constant. Equation 16.5 takes the form H = −kA(dT/dr), where r is the radial coordinate measured from the pipe axis. Use this equation to show that the heat-loss rate from a cylindrical pipe of radius R1 and length L is
where the pipe is surrounded by insulation of outer radius R2 and thermal
Figure 16.16 Problem 76
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