Question

The rate of cooling at $600k,$ if the surrounding temperature is $300K$, is $H.$ The rate of cooling at $900K$ is

• A. $\frac{16}{3}H$
• B. $2H$
• C. $3H$
• D. $\frac{2}{3}H$

Answer 1

The correct option is A $\frac{16}{3}H$

By Stefan's law, Rate of cooling, $H\propto (T^4-T_0^4)$

$\therefore \frac{H\prime }{H}=\frac{{\left(900\right)}^4-{\left(300\right)}^4}{{\left(600\right)}^4-{\left(300\right)}^4}=\frac{9^4-3^4}{6^4-3^4}=\frac{3^4(3^4-1)}{3^4(2^4-1)}$

$\therefore H\prime =\frac{16}{3}H$