A runner moves along the road at 2.0ms^(-1) in still air that is at a temperature of 29.0^(@)C. His surface area is 1.4m^(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^(@)C to the outside air? Coefficient of convection for dry air and bare skin at wind speed 2.0ms^(-1)" is "22W//m^(2)""^(@)C

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

1.	A runner moves along the road at 2.0ms^(-1) in still air that is at a temperature of 29.0^(@)C. His surface area is 1.4m^(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^(@)C to the outside air? Coefficient of convection for dry air and bare skin at wind speed 2.0ms^(-1)" is "22W//m^(2)""^(@)C
Answer» Solution :From EQ. `Q/t=hADeltaT` GIVEN h = Coefficient of CONVECTION = `22W//m^(2)""^(@)C`, `DeltaT=35.0^(@)C-29.0^(@)C=6.0^(@)C,` A = 85% of the surface area of the runner = `85/100xx1.4m^(2)=1.2m^(2)`. `thereforeQ/t=22W//m^(2)""^(@)Cxx1.2m^(2)xx6.0^(@)C=160W`