Star A has twice the Kelvin temperature at its surface as does star B.The amount of energy radiated per unit area from the surface of A is:
A) the same as from B.
B) twice the amount from B.
C) 4 times the amount from B.
D) 16 times the amount from B.

Question

Quizplus · Accepted Answer

The amount of energy radiated per unit area from a star's surface is given by the Stefan-Boltzmann law, which states that the energy radiated per unit area is proportional to the fourth power of the temperature. Thus, if star A has twice the temperature of star B, we raise 2 to the fourth power to get 16. Therefore, star A radiates 16 times as much energy per unit area from its surface as does star B.

Star a Has Twice the Kelvin Temperature at Its Surface