According to Stefan’s law of radiation, a black body radiates the energy from its unit surface area every second where T is the surface temperature of the black body and is known as Stefan’s constant. A nuclear weapon may be thought of as a ball of radius 0.5 m. When detonated, it reaches a temperature of K and can be treated as a black body.
(1) Estimate the power it radiates.
(2) If the surrounding has water at 30°C, how much water can 10% of the energy produced evaporate in 1 s?
(3) If all this energy U is in the form of radiation, the corresponding momentum is p=U/c. How much momentum per unit time does it impart on a unit area at a distance of 1km?
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