Energy cannot be created or destroyed, only transformed. In a system, the change in internal energy is equal to the heat added minus the work done by the system (

Thermodynamics is the study of heat, work, and temperature, and their relation to energy and radiation. It is governed by four laws that dictate how energy can be transferred.

How we move heat against its natural flow to keep food cold. 2. The Rhythm of Waves and Oscillations