What is Sound?
How does sound travel through air?
Air molecules oscillate back and forth.
The effect of _______ on the way the human ear perceives sound is called pitch.
frequency
What are the names of the three bones in the ear?
Hammer, Anvil, and Stirrup
How does the speed of sound waves compare to the speed of light?
They travel much more slowly than light waves.
What is the strength of a sound wave?
Intensity
What are the two types of pulses of a sound wave?
Compression and Rarefaction
Describe the Doppler effect.
frequency is altered by object's motion. Wavelength is lengthened, meaning frequency decreases, meaning pitch goes lower.
What part of the ear do sound waves first enter?
Auditory canal
What type of air makes sound travel faster?
warm
What is the sound level (in decibels) of busy street traffic?
78 dB
Draw how a sound wave interacts with molecules in the air.
spread out region followed by a condensed region - repeating
Name an everyday sound in the infrasonic pitch range.
Seismic vibrations; rumble of jet engines
What happens to the eardrum when the sound wave reaches it?
It vibrates at the same frequency as the waves.
What does "Mach 2" mean?
twice the speed of sound
How do musicians use tuning forks to tune their instruments?
Tuning forks have certain pitches - they can compare their instrument to the pitch and adjust accordingly.
What happens to the pitch when the frequency decreases?
Goes lower.
What decibel range will produce immediate damage to unprotected ears?
130-145 dB
What is the function of the three bones: hammer, anvil, and stirrup?
To amplify the sound
Explain how you can determine how far away a lightning bolt is from you?
Count the seconds and divide by 3 to get the number of kilometers, or by 5 to get the number of miles.
Describe the experiment Robert Boyle did with a watch. What was the result?
Put watch in vacuum glass container and couldn't hear the alarm.
What does ultrasonic meaning?
above audible range
How does the intensity of a sound wave differ if heard from 3 meters vs. 6 meters?
Decreases by a factor of 4
Describe what happens in the cochlea.
It is filled with fluid. Hairs tuned to different frequencies send information about vibrations to the brain.
Find the speed of a sound wave in air when the temperature is 25 degrees Celsius.
346 m/s
Draw the part of a sound wave that is related to intensity.
Amplitude