An experiment is conducted to study the thermal energy balance of two metallic spheres, P P\,P and QQQ, suspended in a sealed, evacuated chamber. The temperature of each sphere is monitored over time as they exchange energy via thermal radiation with the chamber walls, which are maintained at a constant temperature.
At t=100 st = 100\text{ s}t=100 s, both spheres have reached a constant temperature. Which of the following statements correctly identifies the temperature of the chamber walls and describes the thermal radiation exchange at this time?
The temperature of the chamber walls is 300 K300\text{ K}300 K. The net rate of thermal energy transfer between each sphere and the chamber walls is zero.
The temperature of the chamber walls is 300 K300\text{ K}300 K. Sphere PPP has completely stopped emitting thermal radiation because it has reached thermal equilibrium.
The temperature of the chamber walls is 0 K0\text{ K}0 K. The net rate of thermal energy transfer between each sphere and the chamber walls is zero.
The temperature of the chamber walls is 300 K300\text{ K}300 K. Sphere PPP continues to emit more thermal radiation per second than sphere QQQ because its initial temperature was higher.