14.1 A2 Level

Thermal equilibrium

6 flashcards to master this topic

Definition Flip

What is thermal energy?

Answer Flip

Thermal energy is the energy a substance possesses due to the kinetic energy of its particles. The greater the substance's temperature, the greater the thermal energy.

Key Concept Flip

In what direction is thermal energy transferred?

Answer Flip

Thermal energy is always transferred from a region of higher temperature to a region of lower temperature. This transfer continues until thermal equilibrium is reached.

Definition Flip

What does it mean for two regions to be in thermal equilibrium?

Answer Flip

Two regions are in thermal equilibrium when they are at the same temperature and there is no net transfer of thermal energy between them. Both regions have reached a stable state.

Key Concept Flip

Describe, at a microscopic level, what happens when two objects at different temperatures are brought into contact.

Answer Flip

The particles in the hotter object have, on average, greater kinetic energy. Collisions between these particles and the slower-moving particles of the cooler object result in a transfer of kinetic energy, thus increasing the temperature of the cooler object and decreasing the temperature of the hotter object.

Key Concept Flip

Give an example of a system reaching thermal equilibrium.

Answer Flip

A cup of hot coffee left on a table will gradually cool down until it reaches thermal equilibrium with the surrounding room temperature. At this point, the coffee's temperature will no longer decrease.

Key Concept Flip

How does the rate of thermal energy transfer change as the temperature difference between two regions decreases?

Answer Flip

The rate of thermal energy transfer decreases as the temperature difference decreases. The greater the temperature difference, the faster the transfer; the smaller the temperature difference, the slower the transfer.

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13.4 Gravitational potential 14.2 Temperature scales