Sound and optics

Any movement that repeats itself over time around a central point (equilibrium point).

Ears and ossicles moving when hearing, vocal cords vibrating when talking, heart beating, brain activity (EEG waves), and insulin release in pulses.

A system where a mass hanging on a spring moves up and down when pulled and released, following Hooke's law.

The spring force is proportional to displacement, expressed as F = -kx.

Ep = ½ kx².

Ek = ½ mv².

Only the mass and spring constant affect the period of oscillation.

X(t) = A sin (ωt + ϕ).

The restoring force is not linear; it is not harmonic.

T = 2π √(L/g).

Underdamped, critically damped, and overdamped.

The system oscillates with decreasing amplitude.

It is usually red-green color blindness, more common in males due to X-linked genes.

It results in the perception of color.

Red, green, blue.

It creates a secondary color, such as yellow from red and green.

To describe light behavior as a wave, especially when interacting with objects similar in size to its wavelength.

It explains how waves travel and disperse, with each point on a wave front acting as a source of tiny wavelets.

It occurs when a wave encounters an obstacle or passes through a narrow opening, causing the wave to bend or spread out.

It refers to the direction of the electric field in light, with natural light exhibiting all polarization directions.

Light can behave like particles called photons, each with specific energy and momentum.

It is the phenomenon where light knocks out electrons from a material, demonstrating that light consists of photons.

The energy of a photon depends on its frequency, not its brightness.

It converts photons into electrical signals.

It measures the energy of emitted electrons to learn about atomic structure.

Light Amplification by Stimulated Emission of Radiation.

Laser light is coherent, meaning the waves are in phase.

Laser light is very focused and intense.

Laser light is often one color, or monochromatic.

The system returns to rest quickly without oscillation.

The system returns slowly to rest without oscillation.

x(t) = A₀e^(-δt) sin(ωt + ϕ).

An external force is applied regularly, causing a significant response if near the natural frequency.

A = F0/√(k-mw)² + (bw)²

When two waves add up, resulting in a louder sound.

When two waves cancel each other out, resulting in a quieter sound.

Two frequencies very close together create a rhythmic increase and decrease in volume.

It breaks brain waves into components like sound into frequencies, used in EEG and Doppler ultrasound.

They travel as longitudinal waves, causing changes in pressure and density in air or fluids.

They are electromagnetic waves visible to the human eye, with wavelengths between 400-700nm.

A wave that reflects back and forth on a string, forming when the wave's frequency matches the string's natural frequency.

It is how strong or tall the wave is.

The distance from one wave peak to the next.

The time for one full wave to pass.

It is how many waves pass per second, calculated as f=1/T.

It is how fast the wave moves, calculated as c= λ x f.

The amount of energy the wave carries per area and time.

A type of pressure wave in air, liquid, or solid.

As spherical waves in all directions.

The stiffness (elasticity) and density of the material.

Part of it reflects (echo) and part continues through.

How much sound is reflected or transmitted between materials.

The change in frequency of sound when the source moves toward or away from you.

It results in a higher pitch.

A safe, real-time imaging technique that uses sound waves and relies on echoes from tissues.

1-40 MHz, which is too high to hear.

To break kidney or gallstones or assist in bone healing.

Hearing loss, tinnitus, heart problems, and mental health issues.

They push air out, which is needed to make sound.

In the larynx (voice box).

They vibrate, creating sound.

11-15 mm.

17-21 mm.

Shapes and amplifies sound.

It vibrates when sound waves hit it and separates the outer ear from the middle ear.

The three tiny ear bones: Malleus, Incus, and Stapes that pass sound vibrations from the eardrum to the inner ear.

Converts vibrations into nerve signals.

It detects sound and transmits signals to the brain.

How much energy sound carries per area.

A logarithmic scale that compares sound to the quietest sound humans can hear.

The difference between normal air pressure and the pressure caused by a sound wave.

Pascal (Pa).

The hearing threshold (very quiet).

A painful and dangerous sound level.

Lp = 20 × log(p/po) where po = 20 µPa.

3-6 kHz

Light acts both as a wave and a particle (photon).

299,792,458 m/s

The incoming light angle is equal to the reflected light angle (α = β).

A virtual image, as if it were behind the mirror.

They spread out, creating a smaller virtual image.

A virtual and magnified image.

The image is sharper but dimmer.

The image is brighter but blurrier.

Ensures everything remains in sharp detail without background blurriness.

Light bends due to refraction, characterized by the refractive index of the materials.

It occurs when light strikes a boundary at a steep angle, reflecting back instead of passing through.

Dispersion is the splitting of light into different colors when it passes through a material, like a prism.

Geometrical optics treats light as straight rays and models reflection and refraction without covering diffraction or polarization.

Prisms change the direction of light, and lenses can be created by assembling many small prisms.

A convex lens bends light inward to a single point (focus) and is used in devices like magnifying glasses.

A Fresnel lens is a thin convex lens used in lighthouses and projectors, designed to save space and weight.

A concave lens bends light outward to spread the rays and is used to correct myopia (short-sightedness).

Diopter = 1 / focal length (in meters)

Convex lenses, which have positive diopters.

Concave lenses, which have negative diopters.

Their diopters add up.

A lens where its thickness is much smaller than the curvature of its surfaces.

It collects light and focuses it onto the focal plane, creating a real image.

Refracting telescopes (use lenses), reflecting telescopes (use mirrors), and catadioptric telescopes (combine both).

It occurs when light rays hitting the edges of a lens bend differently than central rays, leading to blurry images.

Different colors (wavelengths) focus at various points due to dispersion, causing colored fringes at the edges of bright and dark areas.

It is when light rays traveling in different directions focus at various points, often due to an uneven lens or cornea, leading to blurred vision.

Cornea, pupil, lens, retina, and optic nerve.

It is responsible for most light bending and has a fixed focus.

The white part of the eye that serves as the protective outer layer.

It provides oxygen and nutrients to the eye and is continuously renewed.

To regulate light entry into the eye by varying its size.

It adjusts its shape to focus on objects at different distances, a process called accommodation.

A jelly-like fluid that fills the center of the eye and maintains its shape.

It is the inner lining of the eye where light is detected.

Rods for black/white vision and cones for color vision.

It is the stiffening of the lens with age, corrected with convex lenses.

It occurs when the eye is too long or the cornea is too curved, corrected with concave lenses.

It is when the eye is too short or the cornea is too flat, corrected with convex lenses.

It is caused by an irregular lens or cornea shape, leading to distorted vision, corrected with cylindrical lenses.

There are three types of cones: red, green, and blue.