Chapter 20 Sound

Question 1

Infrasonic

Answer 1

Describes a sounds that has a frequency too low to be heard by the normal human ear.

Question 2

Ultrasonic

Answer 2

Describes a sounds that has a frequency to high to be heard by the normal human ear.

Question 3

Compression

Answer 3

Condensed region of the medium through which a longitudinal wave travels.

Question 4

Rarefaction

Answer 4

Rarefied region (of reduced pressure) of the medium through which a longitudinal wave travels.

Question 5

Forced vibration

Answer 5

The setting up of vibrations in an object by a vibrating force.

Question 6

Natural frequency

Answer 6

A frequency at which an elastic object natural tends to vibrate if it is disturbed and the disturbing force is removed.

Question 7

Resonance

Answer 7

THe response of a body when a forcing frequency matches its natural frequency.

Question 8

Interference

Answer 8

A result of superposing different waves, often of the same wavelength. Constructive interference results from crest-to-crest reinforcement; destructive interference results from crest-to-trough cancellation.

Question 9

Beats

Answer 9

A series of alternate reinforcements and cancellations produced by the interference of two waves of slightly different frequencies, heard as a throbbing effect in sound waves.