LTHS Physics
Name ______________________
Sound Waves Practice
1. What is the speed of sound when the temperature is 25°C?
2. If the speed of sound is 365m/s, what is the temperature? Is this a hot or a cold day?
3. At 10 oC, how far away is a reflecting surface if you hear an echo in 0.274 s?
4. Herds of African elephants are generally spread over large areas. Infrasonic sound waves (sound
waves below the human range of frequency detection) are used by these elephants to locate each
other and to communicate. Sound waves with low frequencies have a greater ability to bend around
obstacles and generally carry further. Scientists have detected sound waves with frequencies as low
as 13 Hz being produced by elephants. Assuming a speed of sound of 350 m/s, determine the
wavelength of these sounds waves.
5. What is the difference in wavelength between
any two white keys on a keyboard if the speed of
sound is 346m/s?
LTHS Physics
Name ______________________
Standing Waves Practice
6. A 4m spring is vibrated to make a standing wave with 3 segments.
a. Draw a picture of the standing wave and determine the wavelength.
b. If you measure 7 oscillations in 5 seconds, what is the wave’s frequency?
c. What is the wave speed?
d. What would be the fundamental frequency?
7. Draw the first two harmonics in the open pipes below:
1st harmonic (fundamental)
2nd harmonic
a. How many wavelengths are in the 1st harmonic?
b. How many wavelengths are in the 2nd harmonic?
c. If the open pipe is 0.35m long, and the temperature is 22°C, what is the fundamental
frequency?
8. Draw the first 3 harmonics in the 0.25m pipes with one closed end below:
a. How many wavelengths are in the 1st harmonic?
b. How many wavelengths are in the 3rd harmonic?
c. How many wavelengths are in the 5th harmonic?
d. If the speed of sound is 344m/s, what is the
frequency of the 5th harmonic?