Level 1 Physics, Earth and Space Science: Energy Concepts

Vocabulary practice flashcards covering mechanical, thermal, and electrical energy concepts from NCEA Level 1 Physics, Earth and Space Science (AS 92047).

Gravitational Potential Energy ($E_p$)

The energy stored in an object as a result of its vertical position or height above the ground, determined by the formula $E_p = mgh$.

Kinetic Energy ($E_k$)

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

Power ($P$)

The rate at which work is done or energy is transferred per unit of time, calculated as $P = \frac{\Delta E}{t}$ and measured in watts ($\text{W}$) or joules per second ($\text{J\,s}^{-1}$).

Latent Heat of Fusion

The amount of heat energy required to change the state of a unit mass of a substance from solid to liquid without changing its temperature ($334\,000\,\text{J\,kg}^{-1}$ for water).

Specific Heat Capacity ($c$)

The thermal energy needed to increase the temperature of a unit mass of a substance by one degree Celsius ($1\,^\circ\text{C}$), specified as $4200\,\text{J\,kg}^{-1}$ for liquid water.

Vacuum Flask (Thermos)

A double-walled vessel engineered to minimise thermal energy transfer to keep hot things hot and cold things cold through features including an inner and outer glass layer, a vacuum gap, a reflective coating, and an insulating stopper.

Vacuum (in Thermal Insulation)

An evacuated space devoid of particles located between container walls that completely stops heat transfer by both conduction and convection.

Reflective Coating

A shiny surface on a vessel's inner walls designed to reduce thermal energy transfer by reflecting thermal radiation back toward the contents or surroundings.

Stopper

A sealed cap or plug at the mouth of a vacuum flask that prevents heat loss or gain via convection currents and evaporative cooling.

Variable Resistor

An adjustable circuit component used to alter total circuit resistance, thereby controlling the overall current and the potential difference across other connected components.

Electrical Resistance ($R$)

The opposition offered by a conductor to the flow of electric current, calculated as $R = \frac{V}{I}$ from voltage and current and represented by the slope of a voltage-current graph.

Electrical Energy ($E$)

The total energy delivered to an electrical device over a period of time, calculated using the relationships $E = P \times t$ or $E = V \times I \times t$ and measured in joules ($\text{J}$).

Temperature

A physical quantity that measures the average kinetic energy of the particles within a substance.

Heat Energy

The thermal energy transferred between systems or objects as a result of a temperature difference.

Convection

The transfer of thermal energy in fluids caused by the circulation of warmer, less dense fluid rising and cooler, denser fluid sinking to replace it.

Air Resistance

The opposing frictional force exerted by atmospheric air against a moving body, causing mechanical energy to be converted into heat and sound and reducing final velocity.

Hotplate Water-Heating Setup

An experimental apparatus comprising an electric hotplate, a liquid-filled glass beaker, and an immersed thermometer used to monitor thermal energy absorption and measure specific heat capacity.