SME
Grade 11 Science
Waves and sound: wave properties, standing waves and the Doppler effect
The main lesson, then each kind of problem it solves.
Waves and sound: wave properties, standing waves and the Doppler effect
Main lesson
A standing wave on a string
Use this for “A 0.65 m guitar string carries waves at 286 m/s. What frequency is its first harmonic?”
A pipe open at both ends
Use this for “A 0.50 m flute-like pipe is open at both ends. What is its lowest note in 343 m/s air?”
A pipe closed at one end
Use this for “A 0.25 m tube is closed at the bottom. What is its lowest note in 343 m/s air, and the next one it can play?”
The Doppler effect
Use this for “A 700 Hz siren passes you at 25 m/s. What pitch do you hear as it comes and as it goes?”
Sound level in decibels
Use this for “A busy street has a sound intensity of 10⁻⁵ W/m². What is its sound level in decibels?”
Transverse or longitudinal?
Use this for “Is a sound wave transverse or longitudinal?”