6. Waves

Question 1

What type of wave is a sound wave?

Answer 1

Longitudinal

Question 2

Which type of vibrations move parallel to the direction of the wave?

Answer 2

Longitudinal

Question 3

Which type of vibrations move perpendicular to the direction of the wave?

Answer 3

Transverse

Question 4

Which waves can’t travel through a vacuum?

Answer 4

Mechanical

Question 5

Which waves can travel through a vacuum?

Answer 5

Electromagnetic

Question 6

Which waves pass their vibrations through particles?

Answer 6

Mechanical

Question 7

What is frequency measured in?

Answer 7

Hertz

Question 8

If one wave passes per second, what is the frequency?

Answer 8

1 Hz

Question 9

How do you work out frequency?

Answer 9

Frequency = 1 / Period

Question 10

What is a period?

Answer 10

How long is takes for the wave to pass a point - messed in seconds

Question 11

Equation for wave speed?

Answer 11

Wave speed = frequency x wavelength

Question 12

Equation for frequency?

Answer 12

Frequency = speed / wavelength

Question 13

Equation for wavelength?

Answer 13

Wavelength = speed / frequency

Question 14

What is the symbol for wavelength?

Answer 14

Lambda

Question 15

What does the angle of incidence equal?

Answer 15

The angle of reflection

Question 16

When light enters a glass cube, which direction does it refract?

Answer 16

Towards the normal

Question 17

What happens when light enters a denser glass block?

Answer 17

The speed of the wave decreases and it refracts towards the normal

Question 18

When the incident ray leaves the glass block, which direction does it go in?

Answer 18

Away from the normal

Question 19

What happens to the speed of the ray it leaves the glass block?

Answer 19

It speeds up and bends away from the normal

Question 20

What is the speed of a wave through a vacuum?

Answer 20

300,000,000 or 3x10 to the power of 8

Question 21

Do different electromagnetic waves carry different amount of energy?

Answer 21

Yes

Question 22

What happens when a ray is absorbed instead of reflected?

Answer 22

It heats up

Question 23

What happens as the energy of a wave increases?

Answer 23

The temperature and hazard increased

Question 24

What happens as the wavelength decreases?

Answer 24

The frequency increases
The energy carried increases 
The waves become more dangerous
The waves diffract less
The waves have a shorter range
The waves carry more information

Question 25

What are the groups in the electromagnetic spectrum?

Answer 25

``` Gamma X-ray Ultraviolet Visible Infrared Microwaves Radio waves ```

Question 26

What type of electromagnetic wave has the highest frequency and energy, and the shortest wavelength?

Answer 26

Gamma

Question 27

What type of electromagnetic wave has the lowest frequency and energy, and the longest wavelength?

Answer 27

Radio waves

Question 28

What are infrared waves used for?

Answer 28

To locate fire, detect humans and night vision

Question 29

What type of wave is a light wave?

Answer 29

Transverse

Question 30

What are radio waves used for?

Answer 30

Radio, TV, telecommunications

Question 31

What are gamma waves used for?

Answer 31

Kills bacteria, radiotherapy, cancer treatment

Question 32

What are microwaves used for?

Answer 32

Radar detection, satellite communications, cooking

Question 33

What are in X-rays used for?

Answer 33

Examine damaged machinery and medical scans

Question 34

What are visible waves used for?

Answer 34

Computers, TV, LED display, to see

Question 35

What are ultraviolet waves used for?

Answer 35

Detect counterfeit banknotes

Question 36

What are the hazards of infrared waves?

Answer 36

Overheating - burning

Question 37

What are the hazards of radio waves?

Answer 37

None

Question 38

What are the hazards of gamma waves?

Answer 38

Cancer mutations to tissue

Question 39

What are the hazards of microwaves?

Answer 39

Damage parts of brain

Question 40

What are the hazards of X-Ray's?

Answer 40

Body cells can be killed by high doses

Question 41

What are the hazards of visible waves?

Answer 41

Intense beam damages eyes

Question 42

What are the hazards of ultraviolet waves?

Answer 42

Sun burn, skin cancer

Question 43

How are sounds made?

Answer 43

When an object vibrates and it causes the layer of air next to it to vibrate

Question 44

Where do sounds travel fastest? Why?

Answer 44

Solids because the particles are closer together

Question 45

Why is the no sound in a vacuum?

Answer 45

Because there are no particles to vibrate and pass on energy

Question 46

What do you need to remember when doing f=v/lambda

Answer 46

MAKE SURE THAT THE WAVELENGTH IS IN METRES, THE TIME IN SECONDS AND FREQUENCY IN HZ

Question 47

What is the range of normal human hearing?

Answer 47

20Hz to 20,000Hz

Question 48

When will sound waves refract?

Answer 48

When air changes temperature (change in medium) - waves will travel slower in cooler air

Question 49

Where does sound refract in the night?

Answer 49

Downwards, the air near the ground is cooler than the air higher up

Question 50

What frequency are ultrasound waves?

Answer 50

Higher than 20,000Hz

Question 51

What is ultrasound used for?

Answer 51

Medical Industrial cleaning and no destructive testing of materials

Question 52

Why does the ultrasound need to be a pulse?

Answer 52

So you can hear the echo

Question 53

How is the time delay for an ultrasound and pulse worked out?

Answer 53

distance = speed x time

Question 54

Why is gel used in ultrasound?

Answer 54

Because then there is more ultrasound absorbed. When there is a big difference between densities lots of it would be reflected.

Question 55

What is the distance in ultrasound?

Answer 55

The way there and back

Question 56

What is the depth in ultrasound?

Answer 56

Just the way there

Question 57

Other uses of ultrasound?

Answer 57

The detection and removal of kidney stones

Question 58

What makes seismic waves?

Answer 58

A sudden release of energy in the earths crust

Question 59

What is used to detect movements of the earths crust?

Answer 59

A seismometer

Question 60

What are the two types of seismic wave?

Answer 60

Primary and secondary

Question 61

Properties of primary waves?

Answer 61

* longitudinal * travels through solids and liquids * travels faster

Question 62

Properties of secondary waves?

Answer 62

* transverse * only travel through solids * travels slower

Question 63

Where does the sun's spectrum peak?

Answer 63

At visible wavelengths