Wave and Sound Basics

Transverse Pulse

A single disturbance where the medium moves perpendicular to the direction the pulse travels (e.g., flicking a rope once).

Transverse Wave

A continuous wave where the medium vibrates perpendicular to the wave's direction (e.g., shaking a rope up and down repeatedly).

Medium of a Wave

The substance a wave travels through (e.g., air, water, or a rope).

Difference Between Transverse Pulse and Wave

A transverse pulse is a single disturbance, while a transverse wave is repeated disturbances.

Key Terms

• Pulse Length: Length of one single pulse.
• Wavelength: Distance between two identical points on a wave (e.g., crest to crest).
• Amplitude: Height of the wave from its rest position (determines loudness/brightness).
• Crest: Highest point of a wave.
• Trough: Lowest point of a wave.
• In Phase: Two waves' crests/troughs align (add together).
• Out of Phase: Crests and troughs cancel each other.

Period and Frequency

• Period: Time for one full wave cycle.
• Frequency: Number of waves per second (Hz).

Interference

• Constructive Interference: Waves combine to make a larger wave.
• Destructive Interference: Waves cancel each other.

Superposition Principle

When waves meet, their effects add up temporarily.

Longitudinal Wave

Medium vibrates parallel to the wave’s direction (e.g., sound waves).

Compression and Rarefaction

• Compression: High-pressure region where particles are close.
• Rarefaction: Low-pressure region where particles are spread out.

Properties of Sound Waves

• Longitudinal.
• Need a medium to travel.
• Have pitch (frequency) and loudness (amplitude).

Reflection of Sound Waves

Sound bounces off surfaces (e.g., echoes).

Echo

Delayed reflection of sound you hear separately.

Technologies Using Sound Reflection

• Sonar: Uses sound echoes to map underwater objects (e.g., ships).
• Ultrasound: High-frequency sound for medical imaging (e.g., baby scans).
• Geophysical Prospecting: Uses reflected sound to find oil/minerals underground.