Physics Term 2-3: Wave Properties

Questions and Answers

What is a wave?

A disturbance/oscillation/vibration that carries energy.

What is the high point of a wave called?

Crest

What is the symbol for wavelength?

λ (lambda)

The speed of a wave is the product of its frequency and its __________.

wavelength Signup and view all the answers

Which of the following are types of waves?

Mechanical Waves Signup and view all the answers

Mechanical waves do not require a medium to travel.

False Signup and view all the answers

What is the law of reflection?

The angle of incidence is equal to the angle of reflection. Signup and view all the answers

What occurs during refraction?

Waves bend as they cross into a different medium Signup and view all the answers

What happens to the frequency of a wave during refraction?

It remains unchanged. Signup and view all the answers

What is an echo?

Sound reflecting from a surface and bouncing back. Signup and view all the answers

How do you calculate the wavelength of a sound wave if the speed is 330 m/s and the frequency is 256 Hz?

1.29 m Signup and view all the answers

The Doppler Effect results in a change in frequency due to the relative motion of the source and the observer.

True Signup and view all the answers

Match the following wave features with their definitions:

Crest = High point of the wave Trough = Low point of the wave Amplitude = Max displacement from rest position Wavelength = Distance from one point on the wave to the same point on the next wave Signup and view all the answers

Study Notes

Wave Properties

Vibrating objects transfer energy via waves, characterized by disturbances in a medium.
Energy is transferred without matter moving along with the wave.
Periodic waves repeat at regular intervals, with energy flowing outward from the vibration source.
Key features:
- Crest: high point of a wave.
- Trough: low point of a wave.
- Amplitude: maximum displacement from rest position, not the wave height.
- Wavelength (λ): distance between identical points in consecutive waves.
- Frequency (f): number of waves per second, measured in hertz (Hz). Period (T) is the time for one wave cycle; T = 1/f and f = 1/T.
- Wave speed (v) is derived from v = fλ.

Wave Classification

Waves are classified based on energy propagation:
- Mechanical waves need a medium (e.g., sound, water).
- Electromagnetic (EM) waves have oscillating electric and magnetic fields and can propagate through a vacuum.
Mechanical waves further split into:
- Transverse waves: particle vibrations are perpendicular to energy flow (e.g., water, EM waves).
- Longitudinal waves: particles vibrate parallel to energy flow (e.g., sound waves).

Reflection and Refraction of Waves

Waves can be reflected from smooth or rough surfaces, illustrating scattering.
Refraction occurs when light passes through different media, bending due to speed change.
The normal is a perpendicular line to the reflection/refractive surface, determining angles of incidence (θi) and reflection (θr) with law: θi = θr.
Wavefronts represent positions of crests, with waves moving perpendicular to these fronts.

Further Refraction

As light transitions between media (e.g., air to glass), it bends. The speed change alters the light path, akin to an axle rolling on different surfaces.
Frequency remains constant during refraction, but wavelength (λ) decreases as wave speed decreases.
Light entering denser media (e.g., glass/water) slows and bends toward the normal; exiting media speeds up and bends away.

Wave Interference

Interference occurs when multiple waves overlap, leading to:
- Constructive interference: peak amplitudes combine, creating a greater resultant amplitude.
- Destructive interference: waves cancel each other out, producing reduced amplitude.
Standing waves develop from the interference of incident and reflected waves, forming nodes (no movement) and antinodes (maximum disturbance).

Sound and Wave Interference

Sound is a mechanical, longitudinal wave, moving through mediums via particle vibrations.
Compressions and rarefactions visually represent sound waves.
The speed of sound in air is approximately 340 m/s and varies in different media.
Example calculation of wavelength for a sound wave at 256 Hz: λ = v/f → λ = 330/256 m = 1.29 m.
Sound waves viewed on an oscilloscope display compression and rarefaction zones.

Beats and Doppler Effect

Beats occur when two sound sources of slightly different frequencies interfere, causing rhythmic volume changes.
The Doppler Effect involves changes in frequency or pitch due to the relative motion of the sound source and observer, increasing frequency as the source approaches.

Description

Explore the fundamental concepts of wave properties in this quiz. Understand how energy is transferred through different types of waves without the transfer of matter. Dive into the characteristics of periodic waves and their oscillations.