8TH GRADE · THERMAL PHENOMENA
Temperature and internal energy
Thermal equilibrium, temperature scales and ways to change internal energy.
The entire theory of the lesson is collected here; you can read it without an account. In interactive mode, the same theory appears as cards, followed by questions. with checking the answer and task, and progress is saved.
Basic Concepts
Thermal equilibrium
The state of contacting bodies in which their temperatures are equal and directed heat exchange ceases.
The thermometer displays the temperature correctly after establishing thermal equilibrium with the body being measured.
Temperature scales
The Celsius and Kelvin scales use the same division size, but different reference points.
Zero degrees Celsius corresponds to approximately 273.15 kelvin, and absolute temperature is never negative.
Internal energy
The sum of the kinetic energy of the chaotic movement of particles and the potential energy of their interaction.
Internal energy is changed by heat transfer or work, for example by heating during friction.
Physical quantities
Absolute temperature
Temperature measured from absolute zero on the Kelvin scale.
Unit: kelvin ·
Celsius temperature
Temperature measured on the Celsius scale.
Unit: degrees Celsius ·
Internal energy
The total energy of thermal motion and interaction of body particles.
Unit: joule ·
Lesson formulas
Relationship between temperature scales
Absolute temperature is numerically higher than Celsius temperature by approximately 273.15.
Related formulas
The same formulas in the reference, with symbols and units.
Tasks on the topic
Statements, answer options and the walkthrough.