Waves

Question 1

What is Amplitude?

Answer 1

Amplitude (A) is the height of a wave from the middle to the top of bottom.

Question 2

What is wavelength?

Answer 2

Wavelength (λ) is the length of a complete wave, from crest to crest; trough to trough; or intercept to intercept.

Question 3

What is timeperiod?

Answer 3

Timeperiod (T) (or just period) is the time taken for one complete wave.

Question 4

What is frequency?

Answer 4

Frequency (f) is the number of waves which pass a point each second, measured in hertz (Hz).

Question 5

What is the equation to find frequency or period?

Answer 5

f= 1/T

T=1/F

Question 6

You find the period using

T = …

Answer 6

T = 1/f

Period = 1 / frequency

Question 7

What is a transverse wave?

Answer 7

A transverse wave is a wave where the particles vibrate perpendicular to the direction the energy travels.

Question 8

Give some examples of transverse waves.

Answer 8

Water waves; radio waves; micro waves; infrared radiation; light; ultraviolet; x-rays; gamma rays.

Question 9

What is a longitudinal wave?

Answer 9

A longitudinal wave is a wave where the particles vibrate in the same direction as the energy travels.

Question 10

Give an example of a longitudinal wave.

Answer 10

Sound.

Question 11

What is the wave equation?

Answer 11

/ \
/ V \
/ f λ \
———-

Question 12

wave speed = …

Answer 12

wave speed = frequency x wavelength

Question 13

V = …

Answer 13

V = f x λ

Question 14

Wave speed is measured in…

Answer 14

Wave speed is measured in m/s (meters per second)

Question 15

Frequency is measured in…

Answer 15

Frequency is measured in Hz (Hertz)

Question 16

Wavelength is measured in…

Answer 16

Wavelength is measured in m (meters)

Question 17

Angle of incidence … angle of reflection.

Answer 17

Angle of incidence = angle of reflection.

Question 18

You measure the angle of reflection from …

Answer 18

You measure the angle of reflection from the norm.

Question 19

What happens in refraction?

Answer 19

When a wave goes through an object such as glass or water (for light waves), the wavelength decreases as the waves slow down. This may cause them to change direction and an image would appear different to where it actually is.

Question 20

When a wave goes through an object such as … or … (for … waves), the wavelength … as the waves …… . This may cause them to …… and an image would appear … to where it actually is.

Answer 20

Water
Glass
Light
Decreases
Slowdown
Change direction
Different

Question 21

What is the order of the electromagnetic spectrum?

Answer 21

Radio waves; microwaves; infrared; visible light; ultraviolet; x-rays; gamma rays.

Question 22

What is the order of the visible colours?

Answer 22

Red, orange, yellow, green, blue, indigo, violet.

Question 23

Radio waves have a … wavelength and a … frequency.

Answer 23

Radio waves have a long wavelength and a low frequency.

Question 24

Gamma rays have a … wavelength and a … frequency.

Answer 24

Gamma rays have a short wavelength and a high frequency.

Question 25

With sound; high amplitude = … …

Answer 25

High amplitude = high volume

Question 26

With sound waves; high frequency = … …

Answer 26

High frequency = high pitch

Question 27

What is four common properties of the waves in the electro magnetic spectrum?

Answer 27

1. They all transfer energy.
2. They are all transverse waves.
3. They all travel at 300000000 m/s, the speed of light in a vacuum.
4. They can all be reflected and refracted.

Question 28

Radio waves have the biggest wavelength and the smallest frequency. Why is this useful for communication?

Answer 28

Long-wave radio can travel a long way because it bends around the Earth.

Short-wave radio reflects off of part of the Earth’s atmosphere.

Question 29

What are the uses of radio waves?

Answer 29

Used for Tv, Bluetooth, WiFi, walkie-talkies.

Question 30

What are the dangers of radio waves?

Answer 30

There are NO DANGERS.

Question 31

What are the uses of microwaves?

Answer 31

Used for cooking in microwave ovens; mobile phones; satellite communications.

Question 32

What are the dangers of microwaves?

Answer 32

They can cause internal heating or body tissue.

Question 33

How do microwave ovens work?

Answer 33

By making water molecules in food vibrate.

Question 34

What are the uses of infra-red?

Answer 34

Used for night vision; thermal cameras; cooking; some kinds of heater.

Question 35

What are the dangers of infrared?

Answer 35

They can cause potential skin burns.

Question 36

What are the uses of visible light?

Answer 36

Used for photography and fibre optic cables.

Question 37

What are the dangers of visible light?

Answer 37

In extreme cases, they can cause blindness.

Question 38

What are the uses of ultraviolet?

Answer 38

Used for security features (secret writing); sun beds; to kill bacteria on food.

Question 39

What are the dangers of ultraviolet.

Answer 39

Dangers include sunburn, blindness, skin cancer.

Question 40

What are the uses of x-rays?

Answer 40

Used for medical scans, airport security.

Question 41

What are the dangers of x-rays?

Answer 41

Dangers include cell mutations leading to cancer and damage to unborn children.

Question 42

What can be used to protect against x-rays?

Answer 42

Lead screens.

Question 43

What are the uses of gamma rays?

Answer 43

Used for sterilisation of food and medical equipment after the package has been sealed; and for cancer treatment (radio therapy).

Question 44

What are the dangers of gamma rays?

Answer 44

They dan damage or kill cells, causing radiation sickness or cancer.

Question 45

And image formed in a plane mirror is… (4 points)

Answer 45

• Back-to-front
• The right way up
• Virtual
• As far behind the mirror as the object is in front.