Light Stuff IDK

Explain the difference between longitudinal and transverse waves?

Longitudinal waves have particle vibrations parallel to wave motion; transverse waves have particle vibrations perpendicular to wave motion.

What types of waves are longitudinal?

Sound waves, seismic P-waves, waves in springs along the direction of motion.

What types of waves are transverse?

Light waves, waves on strings, seismic S-waves.

How are waves on a string different from EM waves?

Waves on a string require a medium to travel; EM waves can travel through a vacuum.

What is a medium?

The material through which a wave travels.

How are frequency and period mathematically related?

f = 1

Define wavelength, crest, trough, frequency, period, wave speed, baseline, nodes?

Wavelength: distance between repeating points; Crest: highest point; Trough: lowest point; Frequency: waves per second; Period: time per wave; Wave speed: distance per time; Baseline: equilibrium line; Nodes: points of no displacement.

What is the mathematical relationship between wavelength, wave speed, and period?

v = λ

What is the mathematical relationship between wavelength, wave speed, and frequency?

v = fλ.

What affects the speed of a wave?

Medium properties such as tension, density, elasticity, temperature.

How can you change the frequency of a wave?

Change the source’s vibration rate.

How can you change the amplitude of a wave?

Increase or decrease the energy of the source.

What does the amplitude of a wave indicate?

The wave’s energy.

What does the amplitude represent for a sound wave?

Loudness.

What does the amplitude represent for a light wave?

Brightness.

What does the frequency of a wave represent for a sound wave?

Pitch.

What does the frequency of a wave represent for a light wave?

Color.

What are EM waves?

Transverse waves consisting of perpendicular electric and magnetic fields that oscillate at right angles to each other and to the direction of wave propagation, capable of traveling through a vacuum without a medium. The electric field oscillates vertically, the magnetic field oscillates horizontally, and the wave propagates in the direction perpendicular to both fields. Frequency and wavelength are inversely related (v = fλ), and the energy of a photon is directly proportional to frequency (E = hf).

Speed of light (c)?

3.0 × 10⁸ m

EM spectrum (low → high energy)?

Radio → Microwave → Infrared → Visible → Ultraviolet → X-ray → Gamma.

How is each section of the EM spectrum different from each other?

Differ in wavelength, frequency, energy, and typical applications.

List the colors of visible light in increasing wavelength?

Violet → Blue → Green → Yellow → Orange → Red.

Why do people see an object as white?

It reflects all wavelengths of visible light.

Why do people see an object as black?

It absorbs all wavelengths of visible light.

Why do people see an object as green?

It reflects green light and absorbs other wavelengths.

What mathematical relationship exists between the wavelength and frequency of light when the wave speed is constant?

Wavelength and frequency are inversely proportional (v = fλ).

Which travels faster: The speed of light in a vacuum or the speed of sound in room temperature air?

Light in a vacuum.

What type of EM light is visible to humans?

Visible light (400–700 nm).

What color of light has the most energy?

Violet.

What is the mathematical representation to connect the frequency of a wave and the energy of a photon?

E = hf.

Using the math rep, how are frequency and energy of a photon related?

Directly proportional; higher frequency → higher energy.

Knowing how frequency and wavelength are related when the wave speed is constant, how are wavelength and the energy of a photon related?

Inversely proportional; shorter wavelength → higher energy.

What light property is involved in light bouncing off a mirror?

Reflection.

What light property is involved in spearfishing that causes you to aim at a different location than where you see the fish?

Refraction.

Describe the difference between transparent, translucent, and opaque materials?

Transparent: allows light through clearly; Translucent: allows light but scatters it; Opaque: blocks light completely.

How does light behave when it reaches each of the following materials: transparent, translucent, and opaque?

Transparent: passes straight; Translucent: passes but scatters; Opaque: absorbed or reflected, does not pass through.

Thomas Young’s experiment showed the wave behavior of light. He observed bright and dark spots on a screen. What light property is involved?

Interference.

Which light property involves the bending of light through an opening or around a boundary?

Diffraction.

Which light property makes 3D movies possible?

Polarization.

Which light property helped Einstein win the Nobel Prize in 1905?

Photoelectric effect.

The photoelectric effect is a light property that supports which model of light?

Particle (photon) model.

What are the three primary colors of light?

Red, Green, Blue.

What happens when the primary colors of light mix together?

They produce white light.

What are the three primary colors of pigments?

Red, Yellow, Blue.

What happens when you mix the three primary colors of pigments together?

They produce dark or brown color.

What happens when white light goes through a blue filter?

Only blue light passes; other colors are absorbed.

Which type of photoreceptors are responsible for seeing color?

Cones.

Explain the appearance of a blue bike illuminated by white light after the light from the bike passes through a green filter and then into your eyes?

Blue light is absorbed by the green filter, so the bike appears black.

What happens to white light when it passes through a transparent color filter?

Only the filter’s color passes through; all other colors are absorbed.

Explain what happens to white light when it passes through a prism?

It separates into its component colors (ROYGBV) due to refraction.