# Glencoe Physics Chapter’s 11 & 12

Law of conservartion of energy
Statement of : within a closed, isolated system, energy can change form, but the total amount of energy is constant.

Reference level
The position at which the potential energy is defined to be zero.

Mechanical energy
The sum of the kinetic and gravitational potential energy of a system.

Kinetic energy
The energy of motion measured in joules.

Gravitational potential energy
Energy stored in earth-object as a result of gravitational attraction between object and earth.

Inelastic collision
A collision, in which the kinetic energy decreases.

Rotational kinetic energy
Energy that depends on an object’s moment of inertia, and it angular velocity.

Thermal energy
Energy that usually makes the temperature of colliding objects rise slightly.

Elastic collision
A collision in which the kinetic energy doesnt change.

Elastic Potential energy
The energy in a compressed spring, or a stretched rubber band.

Thermal Equilibrium
The state at which the rate of energy flow between two objects is equal and the objects are at the same temperature.

Heat
Energy transfered between two objects.

Specific Heat
The amount of energy required to raise the temperature of one unit mass of a substance by one temerature unit of that substance.

Heat of Fusion
The amount of energy needed to melt one kg of a substance.

First law of Thermodynamics
States that the change in thermal energy of an object equals the heat added to the objects minus the the work done by the objects

conduction
the transmission of heat or electricity or sound

Entropy
amount of disorder in a system

Heat Engine
a device that converts thermal energy into mechanical energy

Second law of Thermodynamics
States that natural processes go in the direction that maintains or increases the total entropy of the universe

Convection
the transfer of heat by the movement of a fluid

Heat of Vaporization
The amount of energy required for the liquid at its boiling point to become a gas.