Waves Overview Flashcards

Overview of Waves

• A wave is a disturbance that transmits energy and momentum through a medium without carrying matter forward.
• Particles in matter oscillate while the wave travels onward.

Causes of Waves

• Waves are generated by oscillators or single disturbances, like a vibrating tuning fork or a pebble thrown into water.

Buoy Motion in Water Waves

• A buoy anchored underwater moves up and down as water waves pass but does not travel with the wave itself.
• Water molecules also move in circular motions, not along with the wave.

Types of Waves

• Two fundamental types of waves: Transverse and Longitudinal.

Transverse Waves

• These waves oscillate perpendicular to their direction of travel.
• Found in solids and liquids; light is an example, which can travel through a vacuum.

Longitudinal Waves

• Oscillate parallel to their direction of travel and can occur in solids, liquids, and gases.
• Known as pressure waves due to their compressive nature (e.g., sound waves).

Wave Variables

• Wavelength: Distance between two consecutive peaks (transverse) or compressions (longitudinal).
• Frequency: Number of peaks passing a fixed point per second; controlled by the oscillator's frequency.
• Amplitude: For transverse waves, it’s the height from equilibrium to peak; for longitudinal waves, it’s related to molecular compression, not a distance measure.
• Wave Speed Formula: Speed = frequency x wavelength; faster in denser materials.

Amplitude Measurement in Longitudinal Waves

• Amplitude is tied to the level of molecular compression, not a distance metric like in transverse waves.

Beats Phenomenon

• Created when two sound waves of slightly different frequencies interfere, resulting in fluctuations in sound intensity, characterized by beat frequency determined by the difference in source frequencies.

Sound Wave Characteristics

• Sound waves are three-dimensional, radiating in all directions.

Wave Behavior Near Shore

• Water waves break as they approach the shore due to decreasing depth, causing increased amplitude and decreased wavelength, ultimately leading to curling crests.

Sound Wave Definition

• Sound waves are longitudinal waves traveling through solids, liquids, or gases, with speed varying based on material density.

Superposition of Waves

• When multiple waves travel through the same medium, they overlap without disturbance, creating a resultant wave characterized by constructive (maximum) or destructive (minimum) interference.

Standing Waves

• Appear stationary, often in strings and air columns; created by reflecting waves canceling or enhancing each other at nodes (no motion) and antinodes (maximum motion).

Wavelengths in Fixed-Ended String

• Only harmonics that lead to standing waves persist; the first few harmonics relate to specific fractions of the wavelength.

Wavelengths in Closed-End Air Columns

• A tube closed at one end supports odd harmonics, with different fractions of wavelengths fitting according to harmonic number.

Doppler Effect

• Occurs due to relative motion between the sound source and observer, resulting in perceived frequency changes; a source moving away yields a lower pitch, while approaching yields a higher pitch.