General Science: Electricity, Fluids, Sound, and Light

Vocabulary practice flashcards covering fundamental concepts of electricity, fluid mechanics, sound waves, and optics from Lessons 4, 5, and 6.

Electricity

A form of energy caused by the movement of tiny particles called electrons.

Coulomb's Law

A law describing the electrostatic force of attraction or repulsion between two electrically charged particles at rest, given by the formula $F = k_e \frac{q_1 q_2}{d^2}$.

Electrical Conductor

A material that lets electricity flow through it easily, such as copper, silver, gold, steel, or sea water.

Electrical Insulator

A material that stops or resists the flow of electricity, such as rubber, glass, oil, diamond, or dry wood.

Voltage ($V$)

The electrical pressure or force that pushes electrons through a circuit, measured in volts ($\text{V}$).

Current ($I$)

The rate or speed at which electrons flow past a specific point in a circuit, measured in amperes ($\text{A}$).

Resistance ($R$)

The opposition a material offers to the flow of electric current, measured in ohms ($\Omega$).

Ohm's Law

The principle stating that electric current flowing through a conductor is directly proportional to voltage and inversely proportional to resistance ($V = I \times R$), provided temperature and physical conditions remain constant.

Electric Power ($P$)

The rate at which electrical energy is transferred or used, measured in watts ($\text{W}$) or kilowatts ($\text{kW}$), calculated by multiplying voltage by current ($P = V \times I$).

Energy Efficiency

Using less energy to perform the same task or produce the same result, such as using LED bulbs instead of traditional incandescent bulbs.

Fluid

A liquid, gas, or other material that flows or continuously deforms under an applied shear (tangential) force.

Steady Fluid Flow

A type of fluid motion where fluid properties like velocity, pressure, and density do not change over time at any specific point.

Unsteady Fluid Flow

A type of fluid motion where fluid properties such as velocity, pressure, density, or temperature change over time at a specific point.

Rotational Fluid Flow

Fluid flow in which the fluid elements exhibit rotational motion, causing the angle between intersecting lines of the fluid element to change as it moves.

Irrotational Fluid Flow

Fluid flow in which the fluid elements do not exhibit rotational motion, allowing the fluid to move without changing the angles between boundary lines.

Compressible Fluid

A substance (usually a gas) whose volume and density change significantly when an external pressure or force is applied.

Incompressible Fluid

A substance (usually a liquid) whose density remains nearly constant regardless of changes in pressure.

Newtonian Fluid

A fluid whose viscosity remains constant regardless of how much force, speed, or shear stress is applied to it (e.g., water, milk).

Non-Newtonian Fluid

A fluid that changes its thickness and flow behavior when pushed, squeezed, or shaken, rather than maintaining a constant viscosity (e.g., ketchup, oobleck).

Fluid Pressure ($P$)

The force exerted perpendicularly by a fluid (liquid or gas) per unit surface area ($P = \frac{F}{A}$), measured in pascals ($\text{Pa}$).

Density ($\rho$)

The mass per unit volume of a fluid ($\rho = \frac{m}{V}$), expressing how tightly matter is packed, with the SI unit $\text{kg/m}^3$.

Specific Weight ($\gamma$)

The amount of weight per unit volume of a substance ($\gamma = \frac{W}{V} = \rho g$), with the SI unit $\text{N/m}^3$.

Specific Gravity ($SG$)

The dimensionless ratio of the density of a fluid to the density of water at standard conditions.

Viscosity ($\mu$)

A fluid's internal resistance to flow and sliding deformation caused by internal friction, measured in $\text{Pa}\cdot\text{s}$ or $\text{N}\cdot\text{s/m}^2$.

Surface Tension ($\sigma$)

The force acting along the surface of a liquid per unit length that pulls the surface molecules inward to minimize its surface area, measured in $\text{N/m}$.

Capillarity

The rise or fall of a liquid in a narrow tube due to molecular attraction between the liquid and the solid surface, measured in meters ($\text{m}$).

Vapour Pressure

The pressure exerted by the vapour of a liquid in equilibrium with the liquid itself in a closed container, measured in pascals ($\text{Pa}$).

Pascal's Principle

The principle stating that pressure applied to any part of an enclosed liquid will be transmitted equally in all directions throughout the liquid.

Archimedes' Principle

The principle stating that any object wholly or partially submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object ($F_b = \rho_{fluid} V_{displaced} g$).

Bernoulli's Principle

The principle stating that in a flowing fluid, an increase in speed occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.

Sound

A mechanical vibration that travels through a medium in the form of longitudinal waves, where particles vibrate parallel to the direction of wave propagation.

Medium

Any kind of matter (solid, liquid, or gas) through which mechanical waves like sound can vibrate and travel.

Pitch

The perception of sound wave frequency by the human ear, where higher frequencies produce higher pitches and lower frequencies produce lower pitches.

Sound Amplitude

The magnitude of the maximum disturbance of a sound wave from equilibrium, directly determining the loudness and energy carried by the wave.

Timbre

The property of sound used to differentiate between sounds of the same frequency and loudness, depending on the material through which the sound is produced.

Doppler Effect

The shift in frequency and wavelength of sound waves emitted by a source when there is relative motion between the source and the observer.

Light

A form of energy that travels as transverse electromagnetic waves and does not require a material medium to propagate.

Reflection

The bouncing back of heat or light waves off an object or surface.

Refraction

The bending of light as it moves from one material or medium into another due to a change in speed.

Opaque Material

A substance that does not allow any light to pass through it, preventing objects behind it from being seen.

Translucent Material

A substance that allows only some light to pass through while scattering it, preventing clear image transmission.

Transparent Material

A substance that allows light to pass directly through it with minimal scattering, making objects clearly visible.

Convex Lens

A lens that is thicker at the center than at the edges, which converges light waves inward and makes objects appear larger.

Concave Lens

A lens that is thicker at the edges than at the center, which diverges light waves outward and makes objects appear smaller.

Dispersion of Light

The splitting of white light into its constituent spectrum of colors when it passes through an optical prism.