Sound Intensity and Resonance

The measured intensity of sound depends on both the distance from the source and the _______________ of the sound source.

• frequency

• power

• pitch

• wavelength

A sound has an intensity of 1.0 x 10^-4 W/m² at a distance of 2.0 m from the sound source. What is the intensity at a distance of 4.0 m from the sound source?

• 2.0 x 10^-4 W/m²

• 1.0 x 10^-4 W/m²

• 5.0 x 10^-5 W/m²

• 2.5 x 10^-5 W/m²

The perceived loudness of a sound is measured in

• watts per square meter.

• watts.

• decibels.

• hertz.

When the measured intensity of a sound increases from 1.0 x 10^-4 to 1.0 x 10^-3, the decibel level increases from 80 dB to

• 800 dB.

• 100 dB.

• 90 dB.

• 70 dB.

The decibel level at the threshold of human hearing is

• -1 dB.

• 0 dB.

• 1 dB.

• 10 dB.

In general, the human ear is most sensitive to sounds having a frequency of about

• 20 Hz.

• 250 Hz.

• 1000 Hz.

• 15 000 Hz.

When a string on an acoustic guitar is struck, the hollow body of the guitar vibrates at the same frequency as a result of

• forced vibration.

• compressions.

• resonance.

• plane waves.

Resonance occurs when a force causes an object to vibrate at

• a large amplitude.

• a low pitch.

• any frequency.

• its natural frequency.

Which structures are located in the middle ear?

• hammer

• cochlea

• stirrup

• anvil

What is the structure located in the inner ear that contains minute hairs that detect sound and then transmits the sound waves as electrical frequencies to the brain for interpretation of the sound?

• hammer

• cochlea

• stirrup

• anvil