Which compares the thermal energy found in a piece of coal with the thermal energy found in a newly opened coal mine?

The thermal energy found in a piece of coal is lesser than in the thermal energy in a newly opened coal mine. The newly opened coal mine requires a greater thermal energy to really open it due to its solid structure. Whereas in a piece of coal, it only requires a lesser amount of thermal energy to extract it.

One of the contributing factors to thermal energy is the mass contained in the object, since a piece of coal would have a considerably lesser mass than a coal mine, new or old, the mine will have a larger total store of thermal energy.