Wave Speed Quiz: Test Your Knowledge Of Wave Propagation

Concept: wave speed equation. Wave speed equals frequency times wavelength. This links how fast the wave travels to how often it cycles and how far apart cycles are.

Concept: rearranging (v=fλ). With (v) fixed, (λ = v/f). Increasing (f) makes (λ) smaller.

Concept: using (v=fλ). Multiply frequency by wavelength: (5 × 2 = 10). Units become m/s.

Concept: solving for wavelength. Use (λ = v/f). (12/3 = 4) m.

Concept: medium sets wave speed. In many cases, the medium’s properties (tension, density, stiffness) determine speed. The source sets frequency; the medium adjusts wavelength accordingly.

Concept: sound needs a medium and travels fastest in solids. Sound travels faster where particles are more tightly connected (solids). It cannot travel in a vacuum because there are no particles to vibrate.

Concept: sound requires matter. Sound is a mechanical wave and needs particles to oscillate. In a vacuum, there is no medium to carry the disturbance.

Concept: em waves don’t require a medium. Electromagnetic waves are oscillations of electric and magnetic fields. They propagate through vacuum at speed (c).

Concept: source vs medium roles. The source controls frequency. The medium controls speed, so wavelength adjusts to satisfy (v=fλ).

Concept: amplitude vs speed. In many linear wave systems, speed is independent of amplitude. Speed depends on medium properties, while amplitude mainly affects energy.

Concept: speed units. Speed is distance per time. Wave speed is measured the same way as any speed.

Concept: superposition principle. When waves meet, the total displacement is the sum of individual displacements. This can create larger or smaller resulting waves.

Concept: constructive interference. If crests align with crests (or troughs with troughs), amplitudes add. This increases the resulting wave amplitude.

Concept: destructive interference. Opposite displacements partially or fully cancel. A crest overlapping a trough reduces amplitude.

Concept: wave independence in linear systems. Superposition describes overlap only during meeting. Afterward, waves continue with their original shapes (approximately) in many cases.

Concept: inverse relationship at fixed speed. Since (f = v/λ), larger wavelength means smaller frequency. This keeps (v) unchanged.

Concept: source sets frequency. A speaker cone vibrating at a set rate produces that frequency in the surrounding air. The medium determines how fast the disturbance travels.

Concept: frequency stays, wavelength adjusts. Frequency is fixed by the source at the boundary. If (v) decreases and (f) stays constant, (λ = v/f) decreases.

Concept: reflection of pulses. Boundaries send waves back. How they reflect depends on whether the end is fixed or free, but reflection occurs either way.

Concept: speed–frequency–wavelength triangle. (v=fλ) ties the three quantities together. Understanding which is set by source vs medium helps predict what changes.