Longitudinal Waves

Question 1

Longitudinal waves

Answer 1

A wave in which the particles of the medium vibrate parallel to the propagation of the wave.

Question 2

Compression

Answer 2

A region of a longitudinal wave where the particles are closer together than the rest position.

Question 3

Rarefaction

Answer 3

A region of a longitudinal wave where the particles are farther apart than the rest position.

Question 4

Amplitude of a longitudinal wave

Answer 4

The maximum distance the particles move from the equilibrium

The maximum increase or decrease in pressure.

Question 5

Sound waves in different mediums

Answer 5

Sound travels fastest through solids, slower in liquids and slower still in gasses. Sound does not travel through a vacuum.

Question 6

Pitch

Answer 6

How high or low a sound is. It is related to the frequency of a sound. High frequency = high pitch

Question 7

Loudness

Answer 7

The intensity or volume of a sound. It is related to the amplitude of the sound wave. Small amplitude = soft sound.

Question 8

Quality / Tone

Answer 8

A measure of the quality of a sound. E.g. an A played on a piano is different to an A played on a violin because they have different tones.

Question 9

Sonar

Answer 9

Sound Navigation And Ranging

Question 10

How sonar works

Answer 10

Sound waves can be reflected.
A sound wave is transmitted from the ship and bounces back off the seabed to the ship. Because the speed of sound is known and the time taken can be measured, the distance can be determined.

Question 11

Calculating distance

Answer 11

V = d / t
speed = distance/time

Question 12

Ultrasound

Answer 12

Sound with frequencies higher than 20 000 Hz and less than 100kHz

Question 13

Uses of Ultrasound

Answer 13

Detecting objects and measuring distances
imaging in medicine
detecting invisible flaws in non-destructive testing of products & structures
industrial cleaning and mixing