Waves

Question 1

What’s an oscillation?

Answer 1

When the particle in a wave moves backwards and forwards or up and down yet returns to the starting position however the wave itself moves forwards

Question 2

What are the two types of wave and give some examples of each

Answer 2

Longitudinal- sound,seismic P waves and pressure waves
Transverse - light, sea waves,seismic S waves and Mexican waves

Question 3

What are transverse waves?

Answer 3

The wave oscillates perpendicularly the direction of the motion

Question 4

What angle do each part of the wave move at in a transverse wave?

Answer 4

90 degrees to the direction the energy is moving in

Question 5

Describe a longitudinal wave

Answer 5

The wave moves in the same direction as the direction the energy is going, they move in a plane parallel to the direction of the wave

Question 6

What is a pressure wave?

Answer 6

When you speak to somebody and the air vibrates in longitudinal waves

Question 7

What is amplitude?

Answer 7

The maximum displacement of a wave from its rest position measured in metres (linked with volume)

Question 8

What is wavelength?

Answer 8

The distance between two peaks and two crests measured in meters

Question 9

What is frequency?

Answer 9

The number of oscillations/vibrations per second (linked with pitch)

Question 10

What unit is frequency measured in?

Answer 10

Hertz (hz)

Question 11

If a wave can travel through a substance the wave is what?

Answer 11

Transmitted through it

Question 12

What does opaque, transparent and translucent mean?

Answer 12

Opaque - completely not see through
Translucent - partly see through
Transparent- completely see through

Question 13

In a vacuum what speed does EM waves travel at?

Answer 13

The speed of light (they are transverse waves)

Question 14

The higher the frequency the higher the e…

Answer 14

Energy of the wave

Question 15

What is the only difference between electro magnetic waves?

Answer 15

Frequency and wave length

Question 16

What is the spectrum?

Answer 16

Each colour corresponds to a different wave length

Question 17

Where are violet and red on the spectrum?

Answer 17

Red - the longest - refracted the least in a prism
Violet - the shortest - refracted the most in a prism

Question 18

What are the primary and the secondary colours of light?

Answer 18

Primary colours - Red, green , blue
Secondary colours - magenta, cyan and yellow

Question 19

What do filters do?

Answer 19

They absorb all colours and don’t posses and transmit those that do

Question 20

What do surfaces do?

Answer 20

They absorb all colours and do not posses and reflect those that do

Question 21

What do surfaces do?

Answer 21

They absorb all colours and do not posses and reflect those that do

Question 22

WHen do objects emit radiation?

Answer 22

Due to their temperature - the higher the temperature the greater the amount of infrared emmited

Question 23

When can an object emit visible light?

Answer 23

When it gets hot enough

Question 24

What does infrared cause!?

Answer 24

Causes heat - exposure to small a,lungs warms a person (e.g sunlight)

Question 25

What does large amount exposure to infrared radiation cause?

Answer 25

Burns

Question 26

What does ultraviolet light cause?

Answer 26

- tanning UV - materials to fluorescence (shine with visible light)

Question 27

What could ultraviolet light be used for?

Answer 27

To detect forgeries on bank notes

Question 28

What are the three main categories of ultra violet radiation and their properties

Answer 28

- UVA - longest wave length, tanning, 99% UV light to reach the earth - UV B - medium wave length, damages cells, causes sunburn and skin cancer - UV C - shortest wave length, the most damaging, filtered out by earths ozone layer

Question 29

What type of waves can be reflected?

Answer 29

All

Question 30

What’s the normal?

Answer 30

An imaginary line drawn at 90 degrees to the mirror

Question 31

What’s an incident ray?

Answer 31

When the ray hits the mirror and goes IN the mirror

Question 32

What’s a reflected ray?

Answer 32

When the ray leaves the mirror

Question 33

How do you measure the angle of incidence?

Answer 33

Between the normal and the incidence ray

Question 34

How do you measure the angle of reflection? .

Answer 34

It’s measured between the Normal and the reflected ray

Question 35

What’s the law of reflection?

Answer 35

The angle of incidence = the angle of reflection

Question 36

When do sound and light waves change speed?

Answer 36

When they pass between the boundaries of two different substances with different density’s

Question 37

What is refraction the change of?

Answer 37

Direction

Question 38

At what speed will the light move through a more dense substance?

Answer 38

Slower speed

Question 39

What’s superposition?

Answer 39

When waves meet with each other they create an interference pattern

Question 40

High frequency’s =…

Answer 40

High pitch

Question 41

What is the human hearing range?

Answer 41

Between 20 Hz - 20,000

Question 42

What does the amplitude tell us?

Answer 42

The volume - its an indicator of how much energy is transferred

Question 43

What’s volume measured in?

Answer 43

Decibels (dB)

Question 44

Hard surfaces _______ , soft __________ it

Answer 44

Reflect sound, absorb

Question 45

Flat surfaces ________ , rough _________ it

Answer 45

Reflects sound, scatters

Question 46

What does the electrical current cause the solenoid to become?

Answer 46

Magnetised

Question 47

Since the solenoid is in a magnetic field what happens?

Answer 47

The solenoid experiences a force

Question 48

What causes the magnetic force to either move the solenoid out or into the permanent magnet, due to the change in direction of the force?

Answer 48

Alternating current

Question 49

What does the diaphragm in a speaker do?

Answer 49

Moves the solenoid which causes air molecules near the diaphragm to vibrate

Question 50

What causes the flexible membrane to vibrate back and forth?

Answer 50

The sound wave

Question 51

How is the small electrical current in microphones caused?

Answer 51

The solenoid is moved forwards and backwards through the magnetic field

Question 52

Why does the direction of the electrical current change?

Answer 52

The vibration of the solenoid changing direction

Question 53

Since the signal is weak what needs to be happened in microphones to be used in a loudspeaker?

Answer 53

It needs to be amplified