A piece of iron is heated from 400 K to 800 K (127°C to 527°C). By what factor will the total energy per second emitted by this iron increase?

Question

Quizplus · Accepted Answer

The total energy per second emitted by a body (according to the Stefan-Boltzmann law) is proportional to the fourth power of its absolute temperature (T^4). Therefore, when the temperature is doubled (from 400 K to 800 K), the energy emitted increases by a factor of (800/400)^4 = 2^4 = 16.

A Piece of Iron Is Heated from 400 K to 800