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A runner moves along the road at 2.0 ms^...

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 .

Text Solution

Verified by Experts

From eq. `(Q)/(t) = hA Delta T `
Given h = Coefficient of converction = 22 W/`m^(2)""^(0) C , `
`Delta T = 35.0^(0) - 29.0^(0)C = 6.0^(0)` C ,
A = 85 % of the surface area of the runner
`= (85)/(100) xx 1.4 m^(2) = 1.2 m^(2)` .
`therefore (Q)/(t) = 22 W//m^(2)""^(0)C xx 1.2 m^(2) xx 6.0^(0)C = 160` W
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