Sound Waves

Question 1

What type of waves are sound waves?

Answer 1

Longitudinal

Question 2

What can change the speed of sound?

Answer 2

The medium it’s travelling through

Question 3

What is the speed of sound through air?

Answer 3

330m/s

Question 4

Why can’t sound travel through a vacuum?

Answer 4

Because there are no particles to carry the vibrations

Question 5

Explain how we hear sound

Answer 5

Sound waves enter the ear canal and cause eardrum to vibrate
Three small bones transmit vibrations to cochlea
This produces electrical signals which pass through the auditory nerve to the brain
Then is interpreted as sound

Question 6

How do frequencies affect the pitch of a sound?

Answer 6

High frequency waves are high pitched
Low frequency waves are low pitched

Question 7

How does amplitude affect sound?

Answer 7

High amplitude is loud sound
Low amplitude is quiet sound

Question 8

What is the normal hearing range of a human?

Answer 8

20Hz-20,000Hz

Question 9

What frequency sound is Ultrasounds?

Answer 9

Above 20,000Hz

Question 10

Why can dogs hear ultrasounds and humans can’t?

Answer 10

Different species have different hearing ranges
This is why dogs can hear ultrasounds produced by dog whistles and humans can’t

Question 11

What do people use ultrasounds for?

Answer 11

Breaking kidney stones
Cleaning jewellery

Question 12

How do ultrasounds clean jewellery?

Answer 12

Vibrations cause the dirt on jewellery to shake off

Question 13

How do ultrasounds break kidney stones?

Answer 13

Vibrations cause them to break apart

Question 14

What is ultrasound imaging used for?

Answer 14

Creates a picture of something that cannot be seen directly such as a unborn baby, faults and defects inside manufactured parts

Question 15

What happens when ultrasound waves meet at a boundary between two different materials?

Answer 15

Some ultrasound waves are deflected at boundry
Time taken for waves to leave a source and return to detector is measured
Depth of boundry is determined using speed of sound in material and time taken

Question 16

What is echo sounding used for?

Answer 16

High frequency sounds used to detect objects in deep water and measure water depth

Question 17

How can distance of reflecting surface or object me calculated with echo sounding?

Answer 17

Using the time taken between pulse of sound being transmitted and speed of sound in water

Question 18

What is the difference between echo sounding and ultrasounds?

Answer 18

The sound waves for echo sounding are within normal hearing range and to identify objects rather than internal structure

Question 19

What are seismic waves produced by?

Answer 19

Earthquakes in earths crust

Question 20

What can earthquakes cause?

Answer 20

Damage to structures and tsunamis

Question 21

What are the layers of earth from surface to centre?

Answer 21

Crust
Mantle
Outer Core
Inner Core

Question 22

What are the two types of seismic waves?

Answer 22

P-Waves
S-Waves

Question 23

What are the properties of P-Waves?

Answer 23

Longitudinal
Fast
Travel through solids and liquids

Question 24

What are the properties of S-Waves?

Answer 24

Transverse
Slow
Travel through solids

Question 25

Are S-Waves detected on the other side of Earth and what does this suggest?

Answer 25

They are not detected
This suggests the mantle has solid properties but the outer core must be liquid

Question 26

Are P-Waves detected on the other side of Earth and what does this suggest?

Answer 26

They are detected on the other side of Earth
This suggests refraction between layers cause two shadow zones where no P-Waves are detected
The size and position of shadow zones suggest there is a solid inner core