Physics

Problem

A spherical scientific probe with emissivity

0.35

must continuously radiate away

50\,\text{W}

while its exterior remains at

450\,\text{K}

. Using

\sigma = 5.67\times10^{-8}\,\text{W\,m}^{-2}\text{K}^{-4}

, determine the required radius of the probe in metres.