Unit 12 - Waves

What is the speed of sound at room temperature (20°C)?

• 300 m/s

• 323 m/s

• 343 m/s

• 434 m/s

If an observer hears the sound of a baseball hitting a bat 0.75 s after impact on a day when the temperature is 20°C, how far is the batter from the observer?

• 200.2 meters

• 275.3 meters

• 257.3 meters

• 273.5 meters

A stationary woman on the side of the road hears a siren as an ambulance approaches at 30.0 m/s. If she hears a frequency of 440 Hz, and it is 20°C, what is the frequency of the siren at the source?

• 402 Hz

• 442 Hz

• 452 Hz

• 432 Hz

If a sound wave is traveling when the temperature is 20°C and has a wavelength of 2.45 m, what is the frequency of the sound?

• 130 Hz

• 210 Hz

• 14.1 Hz

• 140 Hz

the change in frequency of sound caused by a moving sound source or a moving observer is known as ______________.

• Sound wave

• Sound level

• Harmonics

• Doppler effect

The unit of measurement for the level of a sound is also known as a(n) _________________.

• Decibel

• Joule

• Hertz

• Angstrom

the logarithmic scale that measures the amplitudes of sounds that humans can hear is called ______________.

• Decibels

• Harmonics

• Sound level

• Loudness

The highness or lowness of a sound, which depends on frequency, is known as _________________.

• Resonance

• Pitch

• Harmonics

• Consonance

An unpleasant, jarring combination of pitches can be called ____________.

• Consonance

• Resonance

• Loudness

• Dissonance

Which of the following can use echoes to determine the distance to an object?

• bats

• cameras

• ships using sonar

• all of the above