Fundamentals of Matter, Waves, and Energy Transfer

Particle Model of Matter

Explains matter as being composed of small particles in constant, random motion, with temperature affecting particle speed.

Conduction

Heat transfer through direct contact, usually in solids.

Particle Model of Matter

Explains matter as being composed of small particles in constant, random motion, with temperature affecting particle speed.

Conduction

Heat transfer through direct contact, usually in solids.

Convection

Heat transfer by movement of fluids (liquids or gases).

Radiation

Transfer of heat through electromagnetic waves, such as sunlight.

Conductors

Materials like metals that easily transfer heat.

Insulators

Materials like rubber or plastic that restrict heat flow.

Wave

A disturbance that transfers energy without moving matter; includes mechanical and electromagnetic types.

Mechanical Waves

Require a medium (such as air, water, or solids) to propagate. Example: sound waves.

Electromagnetic Waves

Do not require a medium and can travel through a vacuum. Examples include light, microwaves, and X-rays.

Transverse Waves

Particles move perpendicular to wave direction (e.g., light waves).

Longitudinal Waves

Particles move parallel to wave direction (e.g., sound waves).

Wave Speed Formula

v=fλ, where v is speed, f is frequency, and λ is wavelength.

Sound Waves

Mechanical longitudinal waves that transfer energy through compressions and rarefactions in a medium.

Pitch

Determined by the frequency of a sound wave; higher frequencies result in higher pitch.

Loudness

Determined by amplitude; greater amplitude results in a louder sound.

Electromagnetic Spectrum Order

From low to high frequency: radio, microwave, infrared, visible light, ultraviolet (UV), X-rays, gamma rays.

Speed of Light vs. Speed of Sound

Light travels faster than sound, particularly in air (300,000 km/s for light vs. 343 m/s for sound in air).

Visible light spectrum

The visible spectrum in order: red, orange, yellow, green, blue, indigo, violet.

Refraction

The bending of light as it passes from one medium to another, such as from air to water.

Direction of Light Bending

Light bends toward the normal when entering a denser medium and away from the normal when entering a less dense medium.

Snell's Law

Describes refraction: n1 sinθ1 = n2 sinθ2, where n is the refractive index of the medium.

Total Internal Reflection

When the angle of incidence is larger than the critical angle

Basic Components of an Electric Circuit

Power supply, conducting pathway, and load.

Ohm's Law

The relationship V=IR, where V is voltage (V), I is current (Amps), and R is resistance (Ohms).

Conservation of Energy

States that energy cannot be created or destroyed, only transformed.

Energy Efficiency Calculation

Efficiency (%) = (useful energy output / total energy input) × 100.

Battery

Switch. (off)

Switch (On)

Resistor

Ammeter

An instrument used to measure the current in a circuit, connected in series with a circuit

Voltmeter

to measure voltage, parallel with the voltage source