Unit 12: Sound

What is period?

• Number of vibrations per second

• Time for one complete vibration

Sounds that are above 20000 Hz are known as

• Ultrasound

• Infrasound

• Range of hearing

What is the range of hearing?

• From 2 to 2000 Hz

• From 20 to 2000 Hz

• From 20 to 20000 Hz

• From 200 to 20000 Hz

What happens to the pitch of the sound if its frequency increases?

• Increases

• Decreases

Sound A has a period of 0.010 s ; sound B has a period of 0.020s. Which one has greater frequency?

• Sound A

• Sound B

The areas of sound wave where the air molecules are close together are called ........................ The areas where air molecules are less closely packed are called ...................

• Rarefaction / Compression

• Compression / Rarefaction

The name of reflected sound is

• Pitch

• Loudness

• Echo

• Period

The unit of frequency is

• Seconds

• Meters

• Hertz

• m/s

A louder sound has a .........

• smaller frequency

• greater frequency

• greater amplitude

• smaller ampliude

Which trace shows the highest amplitude?

• A

• B

• C