P6: Waves

Question 1

Wave defenition

Answer 1

Repeated vibrations / oscillations that transfer energy around a fixed point

Question 2

What is a transverse wave?

Answer 2

Waves where the direction of energy transfer is perpendicular to the direction of vibration

Question 3

Examples of transverse waves (4)

Answer 3

• ripples on water
• guitar string
• em waves
• S waves

Question 4

Which waves can travel in a vacuum?

Answer 4

Only em waves

Question 5

What materials can transverse waves move in?

Answer 5

Solids liquids and gases

Question 6

Do transverse waves have a constant density and pressure?

Answer 6

Yes

Question 7

Do waves transfer matter?

Answer 7

No, only move the particles of the medium and transfer energy

Question 8

What are longitudinal waves?

Answer 8

Waves where the vibrations are parallel to the direction of energy transfer

Question 9

Describe compressions, rarefactions, peaks and troughs

Answer 9

-

Question 10

Examples of longitudinal waves (3)

Answer 10

• sound waves
• p waves
• pressure waves

Question 11

What materials can longitudinal waves move in

Answer 11

Not vacuum, all states

Question 12

Do longitudinal waves have constant density and pressure?

Answer 12

No, changes in both

Question 13

What is a wavefront?

Answer 13

Where waves are viewed from above

Question 14

What is the amplitude of a wave?

Answer 14

The distance from the waves normal, or undisturbed position, to the peak of the wave.

Question 15

Lower amplitude = ?

Answer 15

Quieter sound

Question 16

What is the wavelength of a wave (defenition)

Answer 16

The distance from one point of a wave to another

Question 17

Definition of frequency of a wave

Answer 17

How many waves pass a point per second

Question 18

What happens when a sound wave moves from a denser to a less dense medium?

Answer 18

• wave,eight decreases
• velocity decreases
• frequency remains

Question 19

Why is the speed of sound fatsrer on warm days?

Answer 19

Te particles move faster and transfer sound faster

Question 20

What is specular reflection?

Answer 20

Reflection from a smooth surface in a single direction

Question 21

What is diffuse reflection

Answer 21

Reflection from a rough surface,causing scattering

Question 22

What is the law of reflection?

Answer 22

Angle of incidence = angle of reflection

Question 23

Law of refraction?

Answer 23

Angle of incidence is always greater than angle of refraction

Question 24

What is the humans range of hearing in frequency?

Answer 24

20 - 20,000 hZ

Question 25

What are p waves?

Answer 25

Primary seismic waves detected with a seismometer. -low frequency -can pass through solids and liquids

Question 26

What are S waves?

Answer 26

Secondary seismic waves. - transverse - cannot pass though liquids -slower

Question 27

What is an em wave?

Answer 27

Electromagnetic waves: transverse waves that transfer energy from the source to an absorber

Question 28

Em spectrum order?

Answer 28

Radio waves, microwaves, infrared radiation, visible light, ultraviolet, x rays, gamma rays

Question 29

What is the definition of ionisation?

Answer 29

The removal of oe or more electrons from an atom, leaving it with a charge

Question 30

What are the risks of each em wave?

Answer 30

Micro - heat damage to internal organs Infrared - skin burns Visible light- eye damage X rays- kills cels, mutation, cancer Ultraviolet - eye damage, sun burn, skin cancer Gamma rays,p - ionisation, cancer

Question 31

Uses of each em wave?

Answer 31

Radio - long range communications ( can be reflected of atmosphere ) non ionising Microwaves - food, satellite communications (can pass through atmosphere) non ionising IR - heaters VL- cameras, fibre optic cables (not easily scattered) UV- fluorescent lights, security ink, X rays - generate medical images of bones Gamma rays- sterilised medical tools

Question 32

What is a convex lens?

Answer 32

Bend light rays towards a focal point

Question 33

What is a concave lens?

Answer 33

Diverge rays from focal point

Question 34

What is a real image?

Answer 34

An image that can be projected and appears on the opposite side of the lens

Question 36

What is a virtual image

Answer 36

An image that can’t be projected and appears on the same side of the lens

Question 37

Period of a wave defenition

Answer 37

The time it takes for one wavelength to pass a specific point

Question 38

Rp 10: investigating infrared radiation (coloured tubes) method

Answer 38

1: set up 4 identical flasks painted black, grey, white and silver 2: fill the flasks with hit water ensuring the measurements start from the same initial temperature 3: record the starting temperature the shine a light ten cm away 4: measure the temperature at regular intervals

Question 39

Rp 10 : infrared radiation (coloured tubes) variables

Answer 39

Independent: colour Dependent: temperature Control: identical flasks /tubes Same amount f water Same initial temperature . Same time interval

Question 40

Rp 10 infrared radiation (coloured tubes) errors

Answer 40

Systematic: starting temp Random: thermometer hole? Read thermometer not at eye level