- #1
kingstar
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Homework Statement
On a clear night the Earth loses heat according the equation [itex]\frac{dQ}{dt}[/itex] = [itex]\sigma[/itex]AT4 If the average
temperature of the ground is 10°C, calculate the rate of heat loss, per square metre, by the Earth
and the total heat lost, per square metre, in one hour.
Homework Equations
[itex]\frac{dQ}{dt}[/itex] = AT4
[itex]\sigma[/itex] = 5.7 x 10-8 W m-2 K-4
The Attempt at a Solution
Well I'm not sure how you would do this? I've never been taught this equation and haven't found much information on it via google. So anyways what i did was assuming A was the surface area I found the area using 4[itex]\pi[/itex]r2 = 4 x pi x 6400,000^2 = 5.15x1014
Then Subbed the values into the equation: 5.15x1014 x (10)4 x 5.7 x 10-8 = 2.9 x 1011
I'm assuming this is the rate of heat loss, per square metre because its from a differential equation which is to do with rate of change...but then how do i work out the total heat loss, per square metre, per hour? Would i just times it by 60? :S
Thank You.