Here's why:
* Potential Energy in Coal: Coal stores chemical potential energy in its bonds. This energy is released when the coal is burned.
* Kinetic Energy in Steam: The heat released from burning coal causes water molecules to vibrate faster, increasing their kinetic energy. This kinetic energy is what turns the water into steam.
The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another. In this case, the chemical potential energy in coal is transformed into heat energy, which then increases the kinetic energy of the water molecules.
Important Note: This process is also related to the concept of energy efficiency. Not all the potential energy in the coal is converted into the kinetic energy of the steam. Some energy is lost as heat to the surroundings, and some is used to operate the boiler itself.
