Mechanical Waves: Energy Transfer and Properties

• A mechanical wave is a disturbance that transfers energy through matter.
• Energy is required to initiate a mechanical wave.
• Example: Water droplets create waves in a body of water.
• Water droplet energy comes from kinetic energy.

The Medium

• The medium is the matter through which a mechanical wave travels.
• The medium can be solid, liquid, or gas.
• Particles vibrate but don't travel with the wave, only the energy transfers.

Wave Amplitude

• Wave amplitude is the maximum distance particles move from rest.
• Greater energy creates greater amplitude.
• Small pebble = low-amplitude ripples, large boulder = high-amplitude waves.

Wavelength

• Wavelength is the distance between corresponding points on adjacent waves, represented by λ.
• It's usually measured in meters.
• Shorter wavelengths correspond to higher energy (at the same amplitude).

Wave Frequency

• Wave frequency is the number of waves passing a fixed point in a given time, measured in Hertz (Hz).
• 1 Hz = 1 wave per second.
• Higher frequency = shorter wavelengths = more energy (at the same amplitude).

Period and Frequency

• Period (T) is the time for one full wave cycle.

• Frequency (f) is the number of cycles per second.

• T = 1/f and f = 1/T

• Period and frequency have an inverse relationship.

• Example: 34.2s cycle = 0.029 Hz frequency.

Transverse Waves

• Particles vibrate perpendicular to the wave direction.
• Examples: Rope waves, guitar string waves.
• Crests are the high points of the wave.
• Troughs are the low points of the wave.

Longitudinal Waves

• Particles vibrate parallel to the wave direction.
• Examples: Sound waves, spring waves.
• Compressions are areas where particles are close.
• Rarefactions are areas where particles are spread apart.

Wave Amplitude Revisited

• Wave amplitude is the maximum particle displacement from rest.
• Transverse: amplitude is the height difference between a crest and the resting position.
• Longitudinal: amplitude relates to particle closeness in compressions (closer = higher amplitude).
• Amplitude determined by the energy of the disturbance.

Wavelength and Wave Energy

• Wavelength is the distance between corresponding points on adjacent waves.
• Transverse: distance between two crests.
• Longitudinal: distance between two compressions.
• Shorter wavelengths = higher energy.
• Example: Violet light has the shortest wavelength and highest energy in the visible spectrum.

Wave Frequency and Energy

• Wave frequency is the number of waves per unit time (Hz).
• Higher frequency waves have more energy (at the same amplitude).
• Generating higher frequency requires more energy.

Wave Speed

• Wave speed is the distance a wave travels per unit time.
• Speed = Distance/Time
• Relationship to Wavelength and Frequency: Speed = Wavelength × Frequency (v = λf)
• Wave speed can be calculated if wavelength and frequency are known.
• Wave speed depends on the medium.
• Waves travel fastest through solids and slowest through gases.

Wave Properties and Interactions

• Wave speed is the distance a wave travels per unit of time.
• v = fλ
• v = wave speed
• f = frequency
• λ = wavelength
• Wave speed depends on the medium.
• Waves travel fastest through solids and slowest through gases.

Explore mechanical waves, disturbances transferring energy through matter requiring a medium like solids, liquids, or gases. Understand wave amplitude as the maximum particle displacement from rest, influenced by energy. Learn about wavelength, the distance between corresponding points, and wave frequency, measured in Hertz.