physics

Heat

The transfer of thermal energy from a hotter to cooler object.

Thermal energy transfer

Collisions of particles, where heat moves from warm skin to the cooler thermometer.

Heat absorption

When an object absorbs thermal energy, the value of heat (Q) is positive.

Heat loss

When an object loses thermal energy, the value of heat (Q) is negative.

Conduction

The transfer of thermal energy through direct contact between particles in a solid from hotter to cooler ones.

Convection

The transfer of thermal energy in liquids or gases through the motion of fluid, where heated fluid rises and cooler fluid sinks.

Radiation

The transfer of energy through electromagnetic waves which do not require a medium.

Specific heat

The amount of energy that must be added to a unit mass of a material to raise its temperature by one temperature unit, measured in joules per kilogram per degree Celsius (j/kg·K).

Calorimeter

A device used to measure changes in thermal energy, carefully insulated to minimize energy transfer.

Energy conservation

In a closed system, energy cannot enter or leave but can be transferred between substances.

Elastic collision

A collision in which kinetic energy and momentum are conserved.

Inelastic collision

A collision where kinetic energy decreases but momentum is conserved.

Perfectly inelastic collision

A collision where kinetic energy decreases, and objects stick together, conserving momentum.

Superelastic collision

A collision where kinetic energy increases and momentum is conserved.