MYP Integrated Sciences Waves Key Definitions

The maximum displacement from equilibrium (or, for sound, the maximum pressure variation) of the oscillation.

The range of frequencies that a typical human can hear, about 20 Hz to 20 kHz.

A compression is a region in a longitudinal wave where the particles of the medium are close together, resulting in a high-pressure area.

Constructive interference is a phenomenon where two or more waves meet and combine to form a single new wave with a larger amplitude than the individual waves

Interference in which two waves combine to produce a smaller amplitude (and therefore reduced intensity), often when they are out of phase.

A thin, flexible surface that vibrates to create or detect sound waves.

Diffraction is the spreading out of waves when they pass through a gap or around an obstacle.

The continuous range of all electromagnetic wavelengths and frequencies, divided into regions such as radio, microwaves, infrared, visible, ultraviolet, X‑rays and gamma rays.

A transverse wave made of oscillating electric and magnetic fields, perpendicular to each other and to the direction of travel.

Frequency is the number of complete waves passing a point each second.

Interference is the combination of two or more waves when they overlap in the same region of space.

Ionizing radiation is radiation with enough energy to remove electrons from atoms.

A region of Earth’s upper atmosphere containing charged particles that can reflect some radio waves, extending communication range.

A wave in which the oscillations of the medium are parallel to the direction the wave travels.

The medium is the material through which a wave travels.

A rarefaction is a region in a longitudinal wave where the medium's particles are spread apart, creating a low-pressure region.

Reflection occurs when a wave strikes a surface and bounces back into the original medium.

Refraction is the bending of a wave as it passes from one medium to another, caused by a change in the wave’s speed.

The refractive index of a medium is the ratio of the wave speed in vacuum (or air) to the wave speed in the medium.

Sound is a type of wave, a traveling disturbance that transfers energy from one place to another.

The time taken for one full oscillation (cycle) of the medium at a point.

A wave in which the oscillations of the medium are perpendicular (at right angles) to the direction the wave travels.

Sound with frequency above the upper limit of human hearing (about $20\ \text{kHz}$).

A region with very low gas particle density and pressure, but not necessarily zero particles.