physics 3.1, general properties of wave

What is a mechanical wave?

A wave produced by a vibrating disturbance in a material medium where particles vibrate about a fixed position (e.g., rope, water, sound).

What is a progressive (travelling) wave?

A disturbance that transfers energy from one place to another without transferring matter.

What is the particle vibration direction in a transverse wave?

At right angles (90°) to the direction of wave travel (propagation).

What are the key structural features of a transverse wave?

Crests (humps) and troughs (hollows).

What are examples of transverse waves?

Light/EM waves, water waves, seismic S-waves, and waves on a rope.

What is the particle vibration direction in a longitudinal wave?

Parallel to (along the same line as) the direction of wave travel.

What are the key structural features of a longitudinal wave?

Compressions (particles closer together) and rarefactions (particles further apart).

What are examples of longitudinal waves?

Sound waves, seismic P-waves, and a stretched spring pushed/pulled.

What is wavelength (λ)?

The distance between two consecutive, identical points on a wave (e.g., two consecutive crests). Measured in meters (m) or centimeters (cm).

What is frequency (f)?

The number of complete waves generated or passing a point per unit time. Measured in hertz (Hz).

How does wave frequency relate to its source?

The frequency of a wave is always equal to the frequency of its source.

What is amplitude (a)?

The maximum distance/displacement of a point from its undisturbed (mean) position.

What is wave speed (v)?

The distance moved by a wave crest or point per second in the direction of travel.

What does it mean for points on a wave to be in phase?

Points moving with the same speed in the same direction at the exact same time.

What is a wavefront?

A line on which the disturbance has the same phase at all points (e.g., the crest line in a ripple tank).

What is a ray?

A line drawn at right angles (90°) to a wavefront showing the direction of wave travel.

What is the wave equation formula?

Wave Speed (v) = Frequency (f) × Wavelength (λ) [v = fλ]

How do frequency and wavelength relate at a constant wave speed?

Inversely related: a higher frequency produces a shorter wavelength.

What happens to frequency, wavelength, and speed during reflection at a plane surface?

Frequency (f), wavelength (λ), and speed (v) remain completely unchanged.

What is the law of reflection for waves?

The angle of incidence (i) equals the angle of reflection (r) [i = r].

How do wave speed and wavelength change in deep vs. shallow water?

Deep water: waves travel faster and have a longer wavelength. Shallow water: waves travel slower and have a shorter wavelength.

Why does frequency remain constant during water wave refraction?

Frequency is determined solely by the wave source, so it does not change when moving between depths.

Which way does a wave ray bend when moving into shallow water at an angle?

It bends towards the normal line.

What is diffraction?

The spreading of waves around the edges of obstacles or through gap boundaries.

What gap size produces maximum diffraction?

A narrow gap where the gap width is roughly equal to the wavelength (w ≈ λ), producing circular wavefronts.

What happens when waves pass through a wide gap (w >> λ)?

Wavefronts pass straight through with only slight curvature/spreading at the outer edges.

How does wavelength affect diffraction at a single edge?

Longer wavelengths undergo more noticeable curvature and spreading around an edge than shorter wavelengths.