olphin is swimming at 10 metres per second towards a scuba diver. The dolphin is emitting a ‘welcome’ cry which has a frequency of 2980 Hz. What is the frequency that the diver hears underwater?

Sound is detected when a sound wave causes the eardrum to vibrate. Typically, the diameter of the eardrum is about 8.0mm in humans. When someone yells to you in a noisy environment, the sound intensity at your ear sometimes approximates 2 x 10-6 W/m2. Suppose that the 2 x 10-6 W/m2 of sound you are hearing comes from a janitor cleaning a rug by pulling a vacuum cleaner (at the end of a 1-meter-long tube oriented perpendicularly to the line separating you from the janitor). This person is yelling just over the din of the appliance in order to be heard by you. Estimate the distance between you and the janitor

As a jet plane takes off, at 5.0 m the sound wave intensity is 100 W/m². An observer stands 120 m from the runway. What is the intensity of the sound wave that reaches the observer's ear?

A bat is using echolocation to find insects at night. If the bat emits a high frequency chirp and hears an echo 0.031 s later, how far away is the insect? The temperature of the air that night is 24°C.

Ultrasound reflected from an oncoming bloodstream that is moving at 33.0 cm/s is mixed with the original frequency of 1.50 MHz to produce beats. What is the beat frequency (in Hz)?

The warning tag on a lawn mower states that it produces noise at a level of 99.0 dB. What is this in W/m2?

A person uses a decibel meter to measure the sound from a speaker at 55 dB. A second speaker right next to the first is turned on, and outputs sound with the same intensity as the first. What would the person’s decibel meter read with both speakers playing simultaneously? 58 dB 61 dB 110 dB 55 dB

The sound intensity 50 m from a wailing tornado siren is 0.10 W/m2. What is the sound intensity level 300 m from the siren?

The African cicada is the world’s loudest insect, producing a sound intensity level of 107 dB at a distance of 0.50 m. What is the intensity of its sound (in W/m2) as heard by someone standing 3.0 m away?

The lower limit of the human singing voice is 65 Hz. What is the wavelength of this frequency in 20 °C air? 5.3 m 2.2 x 104 m 65 m 0.20 m