Waves p12 and 11

Question 1

Transverse waves

Answer 1

The direction of oscillation is perpendicular (at right angles)to the direction of wave motion

Question 2

Longitudinal waves

Answer 2

The direction of oscillation is parallel to the direction of wave motion

Question 3

Electromagnetic waves share these properties

Answer 3

electromagnetic waves travel at the speed of light v=3x10^8m/s
Can travel through a vacuum
All transverse waves
High frequency waves have high energy whereas low frequency waves have low energy

Question 4

Sources of radio waves

Answer 4

Alternating current in an electrical circuit creates an electromagnetic wave, a radio wave

Question 5

Radio waves effects on body

Answer 5

Radio waves pass through the body without being absorbed

Question 6

Radio waves what can this type of wave be used for

Answer 6

Broadcasting communications;carrying signals for radio and TV
Navigation and radar
Studying universe: astronomy
Control signals e.g. garage doors
Tracking and automatic identification

Question 7

Sources of microwaves

Answer 7

Satellites
Microwave ovens
The sun

Question 8

Effects on body microwaves

Answer 8

Some wavelengths of microwaves can be absorbed causing heating of cells which may be dangerous

Question 9

Microwaves what can this type of wave be used for

Answer 9

Communications:mobile phones and satellite transmissions
Cooking:heating food in microwave ovens

Question 10

Sources of infrared radiation

Answer 10

Is given off by all objects the hotter the object the more infrared radiation

Question 11

Infrared radiation effects on the body

Answer 11

Mostly reflected or absorbed by the skin, causing some heating too ,it can cause burns if the skin gets too hot

Question 12

Infrared radiation what can this type of wave be used for

Answer 12

Thermal imaging/night vision cameras
Television remote controls
Short range communications
Optical fibres
Security systems
Cooking and heating

Question 13

Sources of visible light

Answer 13

Lightbulbs and the sun

Question 14

Visible light effect on the body

Answer 14

Mostly absorbed or reflected by the skin but can cause some heating effects

Question 15

Visible light what can this type of wave be used for

Answer 15

Vision
Photography
Illumination
Photosynthesis
Fibre optic communication

Question 16

Sources of ultraviolet

Answer 16

Produced by the sun and uv lamps

Question 17

Ultraviolet effects on the body

Answer 17

Damage cells which may cause genetic mutations and cancer and can lead to tissue damage or radiation sickness

Question 18

Ultraviolet what can this type of wave be used for

Answer 18

Sun tan beds
Security markers
Fluorescent lamps
Detecting forged bank notes
Disinfecting water

Question 19

X-rays sources

Answer 19

X-ray tubes produce x-rays when electrons or other particles travelling at high speed are stopped

Question 20

X rays effect on the body

Answer 20

Can cause cell damage by radiation if exposed

Question 21

X rays what can this type of wave be used for

Answer 21

Medical x-rays
Observing the internal structure of objects
Airport security scanners

Question 22

Gamma rays sources

Answer 22

Produced by radioactive substances when unstable nuclei release energy

Question 23

Gamma rays effects on the body

Answer 23

Damages healthy cells in our body but can kill cancer cells

Question 24

Gamma rays what can this type of wave be used for

Answer 24

Sterilising food and medical equipment
Detection of cancer and its treatment
Radioactive tracers to detect where substances go;human bodies, leaky pipes, machinery

Question 25

Electromagnetic spectrum from longest wavelength to shortest wavelength

Answer 25

Radio waves->microwaves->infrared radiation->visible light->ultraviolet->x-rays->gamma rays

Question 26

What is an oscillation

Answer 26

The period of an oscillation is the time it takes for one full oscillation to happen.

Question 27

What is a wave

Answer 27

A wave is a series of oscillations that travel from one place to another, transferring energy.

Question 28

The human eye can only detect

Answer 28

Visible light, the wavelength of visible light ranges from just below 400nm to above 700nm

Question 29

Electromagnetic waves transfer

Answer 29

Energy from a source to an absorber

Question 30

V(wave speed m/s)=

Answer 30

F(frequency Hz) x wavelength(m)