Checklist 9 Acc 2026: Energy and Circuits

Vocabulary terms covering energy systems, formulas, efficiency, resources, and basic electrical circuit components based on the lecture checklist.

Open System

A system that can exchange both matter and energy with its surroundings.

Closed System

A system that can exchange energy but not matter with its surroundings.

Energy Transfer

The movement of energy from one object or location to another.

Energy Transformation

The process of changing energy from one form into another form.

Kinetic Energy ($E_k$)

The energy of an object due to its motion, calculated using the formula $E_k = \frac{1}{2} m v^2$.

Gravitational Potential Energy ($E_p$)

The energy stored in an object because of its position in a gravitational field, calculated using the formula $E_p = mgh$.

Energy Efficiency

The ratio of useful energy output to the total energy input, often expressed as a percentage.

Sankey Diagram

A visual representation of energy flow through a system, where the width of arrows is proportional to the amount of energy.

Renewable Energy Source

A source of energy that is replenished naturally over short periods of time, such as hydroelectricity or solar panels.

Non-renewable Energy Source

A source of energy that exists in limited supply and cannot be replaced in a short timeframe, such as fossil fuels.

Hydroelectricity

The process of producing electrical energy by using the gravitational potential energy of falling or flowing water to turn turbines.

Circuit Diagram

A simplified graphical representation of an electrical circuit using standardized symbols.

Series Circuit

An electrical circuit where components are connected in a single path so that the same current flows through all of them.

Voltage

The difference in electric potential energy per unit charge between two points in a circuit.

Current

The rate of flow of electric charge through a conductor.

Resistance

A measure of how much an object or material opposes the flow of electric current through it.