P6 Homework - Retrieval Practice

Question 1

What are the 2 different types of wave?

Answer 1

Longitudinal (e.g. sound)

Transverse (e.g. light)

Question 2

Give an example of a transverse wave?

Answer 2

Light
All electromagnetic waves e.g. radio / mircowaves / infra-red / visible light / Ultra-Violet / Gamma

Question 3

Give an example of a longitudinal wave?

Answer 3

Sound

Question 4

Describe

a) a transverse wave
b) a longitudinal wave

Answer 4

a) Transverse wave - Movement is perpendicular (at right angles) to energy
b) Movement is parallel to energy

Question 5

Describe 3 differences between light and sound waves

Answer 5

• Light is transverse
• Sound is longitudinal
• Light travels at 300000000m/s
• Sound travels at 330m/s (in air)
• Light can travel through a vacuum
• Sound cannot travel through a vacuum

Question 6

Define these terms

Amplitude
Wavelength
Frequency

Answer 6

Amplitude - Maximum displacement of the wave (e.g. from the middle to the peak)

Wavelength - Distance from peak to peak (or trough to trough)

Frequency - Number of waves per second

Question 7

What are these measured in?
Amplitude
Wavelength
Frequency

Answer 7

Amplitude - Metres (m)
Wavelength - Metres (m)
Frequency - Hertz (Hz)

Question 8

What are the uses of Radio Waves?

Answer 8

Communication

Short waves used for radio and TV

Longer waves can be send radio signals around the world

Question 9

What are the uses of Microwaves?

Answer 9

Communication - Microwaves are used to communicate with satellites

Cooking - Microwaves heat the water in the food

Question 10

What are the uses of Infrared?

Answer 10

Heating - Electric heaters release a lot of Infrared radiation to heat a room

Infrared cameras - create a picture using heat. The hotter the object the more infrared given out

Question 11

What are the uses of Visible light?

Answer 11

Sending data - Optical fibres carry data a long way. The information is sent as light rays that bounce along the fibre

Question 12

What are the uses of Ultraviolet waves?

Answer 12

Energy Efficient Lights

Security pens (ink glows under UV light)

Sunbeds

Question 13

What are the uses of X-Rays?

Answer 13

Checking for broken bones

Treating cancer

Question 14

What are the uses of Gamma Rays?

Answer 14

Treating cancer

Sterilising medical equipment

Medical tracers

Question 15

Which electromagnetic waves are used in medical treatment?

Answer 15

X-Rays - Broken bones / Cancer treatment

Gamma Rays - Cancer treatment / Sterilising equipment

Question 16

What is the Leslie cube experiment designed to investigate?

Answer 16

How different surfaces affect the amount of Infrared radiation emitted (given out)

Question 17

What can you use to investigate how the surface of an object affects the infrared radiation emitted?

Answer 17

Use a Leslie cube (Cube with different surfaces e.g. black, white, shiny, matt)

Fill with hot water

Record the temperature (of infrared) emitted from each side

Question 18

In the Leslie cube experiment, what is the

a) Independent Variable
b) Dependent Variable
c) Control Variable

Answer 18

a) Type of surface
b) Infrared/temperature given off
c) Distance from the cube of the infrared detector/thermometer

Question 19

What are the 4 sides of the Leslie cube like?

Answer 19

Black Matt paint
White Matt paint
Shiny Metal
Dull Metal

Question 20

How does the type of surface affect the Infrared radiation emitted?

Answer 20

Black surfaces emit more infrared radiation than white

Matt surfaces emit more infrared radiation than shiny

Question 21

What is the equation for calculating wave speed?

Answer 21

Wave speed (m/s) = Frequency (Hz) x wavelength (m)

Question 22

Which electromagnetic waves are harmful?

Answer 22

Ultraviolet - can cause skin cancer
X-rays - can cause cancer
Gamma rays - can cause cancer

Question 23

Why are some electromagnetic waves harmful?

Answer 23

UV/X-ray/Gamma
Can cause genes to mutate leading to cancer

Question 24

What equipment can be used to measure calculate the speed of a wave?

Answer 24

The ripple tank

Shallow tray of water
Vibrations create waves
Waves cast shadows on a screen under the tank

Question 25

How can the ripple tank be used to calculate the speed of a wave?

Answer 25

• Vibrations create waves
• Waves cast shadows on a screen under the tank
• Measure the distance of 10 ways. Divide by 10 to get 1 wavelength
• Count time taken for 10 waves. Divide by 10 to get frequency of waves each second
• Use Speed = Frequency x wavelength to calculate speed

Question 26

In the ripple tank experiment, why is it better to measure 10 waves and divide by 10?

Answer 26

Larger measurement is more accurate

Question 27

In the ripple tank experiment, how can you measure wavelength?

Answer 27

Take a picture and measure the distance of 10 waves. Then divide by 10

Question 28

In the ripple tank experiment, how can you measure frequency?

Answer 28

Count how many waves pass in 10 seconds. Then divide by 10

Question 29

In the ripple tank experiment, how can you increase the accuracy of your measurements?

Answer 29

Measure 10 waves and divide by 10

Question 30

What is the order of the electromagnetic spectrum?
How can you remember this?

Answer 30

Radio / Microwaves / Infrared / Visible light / Ultraviolet / X-rays / Gamma

Remember / My / Instructions / Visible / Under / Xray / Glasses

Question 31

Which electromagnetic waves have the longest wavelength?

Answer 31

Radio waves