NS2 Test Bank: NS2-M3C23 - Sound and Sonar

Front

A type of instrument used by fishermen to locate schools of fish beneath their boat; the screen displays water depth, echoes returned from fish.

Back

Fish finder

Front

The speed of sound where you are hiking is 344 m/s. You shout and 2 seconds later you hear your echo. How many meters away is the reflecting surface?

Back

344 meters

Front

What is the difference between active and passive sonar?

Back

Active sonar sends out sound waves; passive sonar receives them.

Front

In what form do sound vibrations enter the surrounding source?

Back

longitudinal waves

Front

A change in the frequency with which waves (as sound or light) from a given source reach an observer when the source and the observer are in motion with respect to each other.

Back

Doppler effect

Front

An instrument for listening to sound transmitted through water

Back

Hydrophone

Front

Which of the following is the most important factor affecting the speed of sound in seawater? Temperature, Distance, Marine life, Pressure, Surface area

Back

Temperature

Front

Choose the answer that corrects the sentence: In a medium with variable density and temperature, waves spread in expanding three-dimensional spheres, losing energy as each sphere expands.

Back

The statement is correct as is.

Front

The change between the highest and lowest frequencies heard and the source frequency.

Back

Doppler shift

Front

In order for the human ear to hear a sound, what is the minimum intensity the sound must be?

Back

10^-12 watts/square meters