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The spectral composition of solar radiation is much the same as that of a black whose maximum emission corresponds to the wavelength 0.48mu m. Find the mass lost by the sun every second due to radiation. Evaluate the time interval during which the mass of the sun diminishes y 1 per cent. |
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Answer» Solution :The black body temperature of the sum may be taken as `T_(Theta) = (0.29)/(0.48 xx 10^(-4)) = 6042K` Thus the radiosity is `M_(e Theta) = 5.67 xx 10^(-8) (6042)^(4) = 0.7555 xx 10^(8)W//m^(2)` ENERGY LOST by SUN is `4pi(6.95)^(2) xx 10^(16) xx 0.7555 xx 10^(8) =4.5855 xx 10^(26)watt` This corresponds to a mass loss of `(4.5855 xx 10^(26))/(9xx 10^(16))kg//SEC = 5.1 xx 10^(9) kg//sec` The sun loses `1%` of its mass in `(1.97 xx 10^(30) xx 10^(-2))/(5.1 xx 10^(9)) sec = 1.22 xx 10^(11)` years. |
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