A trunner moves along the road at `2ms^(-1)` in still air that is at a temperature of `29^(@)C` His surface area is `1.4m^(2)` of which apporoximately `85%` is exposed to the air Find the rate of convective heat loss from his skin at a temperature `35^(@)C` to the outside air ? Coefficient of convection for dry air and bare skin at whind speed `2ms^(-1)` is `22W//m^(2)-C` .

Explanation

`(Q)/(t) = h A Delta theta, h = 22 W//m^(2)-C`
`Delta theta =35-29 = 6^(@)C`
`A =85%` of the surface of the runner
`A = (1.4 xx 85)/(100) = 1.2m^(2)`
`(Q)/(t) = 22 xx 1.2 xx 6 =16W` .