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Question
The emissive power of a sphere of area 0.02 m2 is 0.5 kcal s-1m-2. What is the amount of heat radiated by the spherical surface in 20 seconds?
Solution
Data: R = 0.5 kcal s-1m-2, A = 0.02 m2, t = 20 s
Q = RAt = (0.5)(0.02)(20) = 0.2 kcal
This is the required quantity.
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