Physics - thermal energy Flashcards
What is a system?
A system is an object or group of objects
What are the various ways in which
energy can be stored in a system?
What are the different energy stores?
- thermal store
- elastic store
- kinetic store
- gravitational store
- chemical store
- electrostatic store
- nuclear store
- magnetic store
Thermal store
energy due to an object’s temperature. Thermal stores increase when the object gets hotter and decrease when it gets colder
Elastic store
energy due to an object having a greater/shorter length than its natural length. Elastic stores increase if the object is stretched or squashed from its natural shape and decrease if it returns to its natural shape.
Kinetic store
energy due to an object’s mass and speed. Kinetic stores increase if an object’s speed increases and decrease if an object is slowed down.
Gravitational store
energy due to an object’s height above the Earth’s surface. Gravitational stores increase if an object is lifted up and decrease if it falls down.
Chemical store
energy due to atoms combining in a chemical reaction.
Electrostatic store
this is energy stored when similar charged objects are pushed together and when opposite charged objects are pulled apart.
Nuclear store
this is energy associated with the nucleus of an atom. This changes if changes happen in the nucleus e.g. in a fusion reaction
Magnetic store
this is the energy stored when like poles of a magnet are pushed closer together and unlike poles are pulled further apart.
How can energy transfers take place?
Energy transfers happen because of: forces doing work, a flow of an electrical current, heating, light radiation, and sound waves
What is internal energy?
Internal energy is the total kinetic and potential energy of all the particles (atoms and molecules) that make up a system. The molecules’ kinetic store is related to how fast they are moving, and the
molecules’ potential store is related to how far apart they are (their bonds).
