A runner moves along the road at 2.0 ms^(1)in still air that is at a temperature of 29.0^(0)C. His surface area is 1.4 m^(2), of which approximately 85% is exposed to the air. Find the rate of convective heat loss from his skin at a temperature 35.0^(0) C to the outside air? Coefficient of convection for dry air and bare skin at wind speed 2.0 ms^(-1)' is 22 W/m2""^(@) C .

A runner moves along the road at 2.0 ms^(1)in still air that is at a t

1.	A runner moves along the road at 2.0 ms^(1)in still air that is at a temperature of 29.0^(0)C. His surface area is 1.4 m^(2), of which approximately 85% is exposed to the air. Find the rate of convective heat loss from his skin at a temperature 35.0^(0) C to the outside air? Coefficient of convection for dry air and bare skin at wind speed 2.0 ms^(-1)' is 22 W/m2""^(@) C .
Answer» Solution :FromEq. `(Q)/(t) = lambda A Delta T ` Given `lambda ` = Coefficientof conduction ` = 22 W // m^(2 0) C, Delta T= 35.0^(@)C - 29.0^(@)C = 6.0^(@)C` A =85% of the surfacearea of the runner `1.4m^(2) = 1.2 m^(2)` UPON substituting the value `(Q)/(t) = 22W // m^(20)C xx 1.2 m^(2) xx 6.0^(@)C = 160 W `