Problem #$2$

$4$ points

A person is found dead at $5p.m.$ in a room whose temperature is $20C.$ The temperature of the

body is measured to be $25C$ when found, and the heat transfer coefficient is estimated to be $8$

$\frac{W}{m^2}C.$ Modeling the body as a $30-cm$ diameter, $1\mathrm{.}70-m-$long cylinder and using the lumped

system analysis as a rough approximation, estimate:

a$)$ The time of death of that person $(1$ point$)$

b$)$ Explain why is the lumped system a rough approximation? $(1$ point$)$

c$)$ What do you think the actual time of death was? Earlier, later or the same as the answer

in a$)?$ Explain $(2$ points$)$