Unit 1: Energy and Mechanical Interactions & Energy Transfer

Comprehensive vocabulary flashcards covering energy forms, mechanical interactions, conservation of energy, and heat transfer mechanisms for Grade 8 Science.

Energy

The ability to do work or cause changes in matter, giving objects and systems the power to move, transform, or interact.

Kinetic Energy

The energy an object possesses because of its motion, which can exist as the motion of the object as a whole or as internal motion of its particles.

Sound Energy

A form of kinetic energy associated with the vibration of particles through a medium such as steel, water, or air.

Thermal Energy

The total amount of kinetic energy of all the particles that make up a substance or object, measured in joules ($\text{J}$).

Electrical Kinetic Energy

A form of kinetic energy resulting from the movement of electric charges.

Electromagnetic Energy

The kinetic energy carried by moving waves, including visible light, X-rays, and microwaves, which do not require matter to travel.

Potential Energy

The stored energy an object possesses because of its position, condition, or chemical composition.

Gravitational Potential Energy ($\text{GPE}$)

The potential energy an object possesses due to its position relative to another object, such as Earth, calculated using $\text{GPE} = mgh$.

Chemical Energy

The potential energy stored within the chemical bonds of substances, depending directly on the position and arrangement of their atoms.

Elastic Energy

The potential energy stored in an object when an external force acts on it to deform or change its shape.

Magnetic Potential Energy

The potential energy stored in magnetic objects due to their position relative to other magnets or magnetic fields.

Law of Conservation of Energy

The physical law stating that energy cannot be created or destroyed; it can only change from one form to another.

Mechanical Energy ($\text{ME}$)

The total energy possessed by an object due to its motion and position, equal to the sum of its kinetic energy and potential energy ($\text{ME} = \text{KE} + \text{PE}$).

Simple Energy Transformation

The process occurring when energy changes from one form or type into a different form (such as chemical energy converting into kinetic energy).

Simple Energy Transfer

The process occurring when the same type of energy moves from one object or place to another (such as kinetic energy passing from a bowling ball to pins).

Heat

The transfer of thermal energy from a hotter object to a cooler object driven by a difference in temperature.

Thermal Equilibrium

The state reached when two interacting objects reach the exact same temperature, causing heat transfer between them to cease.

Temperature

A measure of the average kinetic energy of all the individual particles in an object or substance, measured in degrees Celsius ($^{\circ}\text{C}$).

Conduction

The transfer of thermal energy between substances through the direct physical contact of colliding particles.

Convection

The transfer of thermal energy in fluids (liquids and gases) caused by warmer, less dense fluid rising and cooler, denser fluid sinking.

Convection Currents

Circular fluid circulation patterns driven by density differences where heated fluid rises and cooler fluid sinks.

Radiation

The transfer of thermal energy through empty space by electromagnetic waves without requiring a medium of matter.

Thermal Conductivity

A physical property describing how easily and quickly thermal energy moves through a given material.

Thermal Conductor

A material possessing high thermal conductivity (such as copper, aluminum, or iron) that allows thermal energy to flow through it quickly and easily.

Thermal Insulator

A material possessing low thermal conductivity (such as wood, plastic, foam, or air) that slows down the movement of thermal energy.

Specific Heat Capacity ($c_p$)

The amount of heat energy required to raise the temperature of $1\,\text{kg}$ of a substance by $1\,^{\circ}\text{C}$.