Waves

Question 1

What are the 2 types of waves?

Answer 1

Transverse
Longitudinal

Question 2

What is a wave?

Answer 2

Transfer of energy from one place to the other

Question 3

What happens in a transverse waves?

Answer 3

Oscillations are perpendicular to the direction of energy transfer

Question 4

What happens in a longitudinal wave?

Answer 4

Oscillations are parallel to the direction of energy transfer

Question 5

What do all waves have?

Answer 5

Frequency, amplitude, wavelength, period

Question 6

Describe frequency

Answer 6

The number of waves passing a fixed point per second, measured in hertz

Question 7

Describe amplitude.

Answer 7

The maximum displacement that any particle achieves from its undisturbed position in metres

Question 8

Describe wavelength

Answer 8

The distance from one point on a wave to the equivalent point on the next wave in metres

Question 9

Describe period

Answer 9

The time taken for one to complete oscillation in seconds

Question 10

What is the speed of a wave?

Answer 10

The speed at which the energy is transferred

Question 11

What do you do when constructing a ray diagram?

Answer 11

Rays must be drawn using a ruler
Single arrow
All relevant angles labelled

Question 12

What does the direction of refraction depend on?

Answer 12

The angle at which the wave hits the boundary, the materials involved

Question 13

What causes refraction?

Answer 13

The difference in the wave speed in the different media

Question 14

What do sound waves have?

Answer 14

Frequency, amplitude and wavelength

Question 15

What is the normal range of human hearing?

Answer 15

20Hz to 20,000Hz

Question 16

What happens when sound waves reach the ear?

Answer 16

The ear drum vibrates

Question 17

What frequency are ultrasonic waves?

Answer 17

greater than 20,000Hz, so they cannot be heard by human ears

Question 18

What happens when an ultrasonic wave meets a boundary between two different media?

Answer 18

It is partially reflected

Question 19

What is ultrasonic waves used for?

Answer 19

Pre-natal scanning, detection of kidney stones and tumours, and producing images of damaged ligaments and muscles

Question 20

What are echo sounds used for?

Answer 20

Detecting objects in deep water and measuring the depth of water

Question 21

What are the 2 types of seismic waves?

Answer 21

P-waves (primary)
S-waves (secondary)

Question 22

What are P-waves?

Answer 22

Longitudinal waves
Travel at the speed of sound (double S-waves)
Travel at different speeds through solids and liquids

Question 23

What are S-waves?

Answer 23

Transverse waves
Not able to travel through liquids

Question 24

What happens during an earthquake?

Answer 24

Seismic waves travel outwards from the earthquake and are capable of travelling all the way through the Earth
Seismic waves travel in a curved path through the earth, due to the earth increasing in density with depth
Detectors placed around the earth measure when and where the different waves arrive

Question 25

What happens in the S-wave shadow zone?

Answer 25

S-waves are not able to travel through the liquid outer core of the earth This results in a large shadow zone on the opposite side of the earth to where the earthquake originated

Question 26

What happens in the P-wave shadow zone?

Answer 26

P-waves are able to travel through the liquid outer core They are refracted at the boundary between the semi-solid mantle and the liquid outer core They are refracted again at the boundary between the liquid outer core and solid inner core

Question 27

What are electromagnetic waves?

Answer 27

Transverse waves

Question 28

What do electromagnetic waves travel through?

Answer 28

In air or a vacuum at the speed of light

Question 29

How does the wavelength of an electromagnetic wave affect it?

Answer 29

Affects how it is absorbed, transmitted, reflected or refracted by different substances, changes his uses

Question 30

What are radio waves caused by?

Answer 30

Oscillations in electrical circuits

Question 31

What are the hazards of Electro magnetic waves?

Answer 31

Ultraviolet waves can cause the skin to age prematuarly and increase risk of skin cancer X-rays and Gamma rays cause ionising radiation that can damage skin cells

Question 32

What does a lens form?

Answer 32

An image by refracting light

Question 33

What are the 2 main types of lens?

Answer 33

Concave Convex

Question 34

How is a convex lense structured?

Answer 34

Wider in the middle than at the edges

Question 35

How is a concave lense structured?

Answer 35

Wider at the edges than it is in the middle

Question 36

What do you do when drawing a ray diagram?

Answer 36

Principle axis Use the correct lense symbol Mark the principle foci on either side of the lens by drawing a dot on the principle axis and labelling it Mark the position of the object as an arrow standing on the principle axis Draw the light rays

Question 37

What is magnification?

Answer 37

The ratio of image height to object height

Question 38

What is visible light?

Answer 38

Describes electromagnetic waves that can be detected by the human eye

Question 39

What is specular reflection?

Answer 39

Reflection by a smooth surface in a single direction

Question 40

What is diffuse reflection?

Answer 40

Reflection from a rough surface, where the light is scattered

Question 41

What do all bodies emit and absorb?

Answer 41

Infrared radiation

Question 42

What does the rate at which an object emits radiation depend on?

Answer 42

The nature of the surface and on its temperature

Question 43

What does the temperature of an object depend on?

Answer 43

The rate at which it emits radiation The wavelength of the radiation it emits

Question 44

What is the temperature of an object related to?

Answer 44

the balance between radiation absorbed and radiation emitted

Question 45

What does the temperature of the earth depend on?

Answer 45

How much energy it recieves from the sun How much energy is reflected back into space How much energy it emits into space