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SOUND WAVES WHAT DOES THE GRAPH TELL US? Michael Smythies 19. February 2015

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SOUND WAVES WHAT DOES THE GRAPH TELL US?

Michael Smythies19. February 2015

What is a sound wave?

• Mechanical waves are made by vibrating objects which disrupt surrounding particles into vibrational motion transporting energy through a medium such as water or air

• Longitudinal waves compress and extend in the direction of net movement

• Series of rarefactions and compressions that create high and low pressure zones

What does a sound wave look like?

Compression(High pressure)

Rarefaction (Low Pressure)

S(x,t)= smcos(kx-ωt+Φ)

Sm: Maximum displacement K: Wave number, k=2π/λω: Angular frequency, ω=2πfΦ: Phase constant

V=fλ=ω/kV: speed of sound wave F: Frequency λ: Wavelength

Equations:

Amplitude

Amplitude is the maximum distance the wave travels from the equilibrium position or distance of wave compression.

Ampl

itude

Frequency: f= 1/Tω=2πf=2π/T

Frequency is the rate in which the wave passes one point.

Frequency

Velocity: V=fλ=ω/k

The speed of sound at sea level and at 20° C is 344 m/s. To calculate the velocity of a wave, you multiply the wavelength by the frequency.

Practice Questions:

Write the equation to this wave function

Answer:

Another one..

Answer:

Practice makes perfect..

Answer: