Chapter 14, Problem 55GP

To determine

To find: The rate of conduction of heat from interior of body to surface.

Answer to Problem 55GP

The rate of conduction of heat from interior of body to surface $\approx 20W$ .

Explanation of Solution

Given Data:

  $k=0.29w/mk$

Thickness of tissue,

  $=4\times {10}^{-2}m$

  $\begin{array}{l}\Delta T={\left(37-34\right)}^{\circ }C\\ =3^{\circ }C\end{array}$

Surface Area of the body, $A=1.5m^2$

Formula used:

Rate of heat flow,

  $\frac{\Delta Q}{\Delta t}=\frac{kA\Delta T}{l}$

Calculation:

  $\begin{array}{l}\frac{\Delta Q}{\Delta t}=\frac{kA\Delta T}{l}\\ \begin{array}{l}=\frac{0.2\times 1.5\times 3}{4\times {10}^{-2}}\text{W}\hfill \\ =22.5\text{W}\hfill \end{array}\end{array}$

Hence, rate of heat flow $\frac{\Delta Q}{\Delta t}\approx 20W$ .

It is very less than measured value of $230watt$ that must be dissipate lightly working person.