Sound

Question 1

Definition of ‘sound’

Answer 1

A form of energy that is transferred from one point to another as a longitutinal wave.

Question 2

How is sound produced?

Answer 2

Sound is produced by vibrating sources placed in a medium.

Question 3

What are compressions and rarefactions?

Answer 3

Compressions - regions where air pressure is higher than the surrounding air pressure

Rarefactions - regions where air pressure is lower than the surrounding air pressure

Question 4

What is the loudness of a sound related to?

Answer 4

Larger amplitude - louder sound

Question 5

What is the pitch of a sound related to?

Answer 5

Higher frequency - higher pitch

Question 6

Definition of ‘echo’

Answer 6

The repetition of a sound due to the reflection of sound.

Question 7

Uses of echoes

Answer 7

Measure large distance ; detect location of objects

Question 8

Definition of ‘ultrasound’

Answer 8

Sound with frequencies above the upper limit of the human range of audibility, above 20kHz.

Question 9

Uses of ultrasound

Answer 9

Quality control ; Prenatal screening

Question 10

Why is a medium required in order to trasmit sound waves?

Answer 10

A molecule of a matter is needed to carry energy from one point to another. There are no matter in vacuum.

Question 11

Why is the speed of sound different in air, liquids and solids?

Answer 11

The distance between each molecules is different for different matter, thus the time taken to transfer energy is different as well.