🔋college physics i – introduction review

Thermal energy

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Thermal energy is the internal energy of a system due to its temperature. It arises from the random motions of atoms and molecules within the system.

5 Must Know Facts For Your Next Test

  1. Thermal energy is a form of kinetic energy resulting from the motion of particles in a substance.
  2. The amount of thermal energy depends on both the temperature and the mass of the system.
  3. Heat transfer occurs when there is a difference in temperature between two systems, resulting in thermal energy flowing from hotter to cooler regions.
  4. In thermodynamics, thermal energy is often measured in joules (J) or calories (cal).
  5. The concept of thermal equilibrium refers to two systems reaching the same temperature and thus no longer exchanging thermal energy.

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