Waves- Paper 2

Question 1

How do waves transfer energy?

Answer 1

.Waves travel through a medium, the particles of the medium oscillate and transfer energy between each other

Question 2

Amplitude?

Answer 2

wave is the maximum displacement point on the wave from its undisturbed position.

Question 3

Wavelength?

Answer 3

.distance between the same point two adjacent waves

Question 4

Frequency?

Answer 4

.number complete waves passing certain point per second.
Frequency measured in hertz (Hz). 1 Hz is I wave per second.

Question 5

period of a wave and a period equation?

Answer 5

.find period of a wave using: amount of time it takes for a full cycle of the wave and frequency.

Period (s)=1/frequency (HZ)

Question 6

Transverse waves: how do they oscillate?
What waves are transverse?

Answer 6

1.oscillations are perpendicular direction of energy transfer.
2.Most waves are transverse:
All electromagnetic waves, waves in water

Question 7

Longitudinal Waves oscillations?
What types of waves are there

Answer 7

.oscillations parallel to direction energy transfer.
.Sound waves, ultrasound.

Question 8

What is wave speed?
What is the equation for wave speed?

Answer 8

.wave speed: speed at which energy is being transferred
.wave speed (m/s)= frequency (HZ)x wavelength (m).

Question 9

How to use Oscilloscope to Measure the Speed of Sound?

Answer 9

1)attaching signal generator speaker=generate sounds specific frequency
2) Set up oscilloscope so detected waves each microphone shown as separate waves.
3)Start both next to the speaker move slowly away the two waves alone display one wavelength apart.
4)Measure distance between microphones one wavelength.
4) wave speed (m/s)= frequency (HZ)x wavelength (m)
5) speed sound in air 330 m/s

Question 10

How to Measure the Speed of Water Ripples Using a Lamp? 6

Answer 10

1. Ripple tank depth 5mm
   2.dipper signal generator attached know frequency
   3.screen below and a dim light
   4.shows the patterns of the ripples
   5.distance with the ruler each shadow line 10 wavelengths
   Apart with a metre ruler
   6.Then divide by 10 for average one wave length

=improve accuracy take digital photo shows use that measure 10 waves lengths

Question 11

How to use Wave Equation for Waves on Strings? 4

Answer 11

1)Attach a string vibration signal generator-200 gram (g) hanging mass pulley=taut
2)Switch vibration generator=stationary waves can be clearly observed.
3)Measure length half wavelengths (loops) as possible, divide by number of half wavelengths=half wavelength, doubling= wavelength.
4)frequency power supply=wave speed = frequency × wavelength.

Question 12

When waves arrive at a boundary between two different materials, three things can happen and why?

Answer 12

1)waves absorbed= material wave cross into - this transfers energy materials energy stores- matt
2)waves transmitted=waves carry on travelling through new material=refraction.
3) waves reflected= bounce back- shiny depends wavelength wave, properties of the materials involved

Question 13

1)What is the angle of incidence and what is the one important rule?
3) what is the angle of reflection?
4) what is the normal?

Answer 13

1)Angle of incidence = Angle of reflection
angle of incidence= angle between incoming wave and the normal.

3)angle reflection=angle between reflected wave, normal.

4)normal=imaginary line perpendicular surface point of incidence (wave hits the boundary). dotted line.

Question 14

1)How and why Reflection can be Specular or Diffuse?
2) Specular reflection?
3) diffuse reflections?

Answer 14

1)Waves are reflected different boundaries different ways, the normals will be different
2)Specular reflection=wave is reflected in single direction by smooth surface all normals are the same
3)Diffuse reflection=wave is reflected by a rough surface and reflected rays are scattered lots of different directions. normal is different for each incoming ray=angle of incidence is different.= not clear matte surface no reflection

Question 15

Diffuse diagram?

Answer 15

Question 16

Specular diagram?

Answer 16

Question 17

How do lenses form images and the two types?

Answer 17

-Lenses form images by refracting light
two main types lens - convex and concave.

Question 18

What is the axis of a lens?

Answer 18

.axis of a lens is a line passing through the middle of the lens.

Question 19

Why do Different Lenses Produce Different Kinds of Image? 3 per lens

Answer 19

1) convex lens
-bulges outwards.
-causes rays of light parallel to the axis (converge) at the principal focus.

1)concave lens
-caves inwards.
-parallel rays of light to spread out (diverge).
-principal focus of a concave lens is the point where rays hitting the lens parallel to the axis,trace them back until they all appear to meet up point behind lens.

Question 20

What is the focal length?

Answer 20

. principal focus on each side of the lens= distance from centre of the lens to the principal focus= focal length.

Question 21

What are the colours of visible light?

Answer 21

Roygbv= red orange yellow green blue violet

Question 22

What are the Three Rules for Refraction in a Convex Lens?

Answer 22

1) incident ray parallel axis refracts lens, passes through principal focus other side.
2) incident ray passing principal focus, refracts through the lens and travels parallel to the axis.
3) incident ray passing through the centre of the lens carries on in the same direction.

Question 23

what are Three Rules for Refraction in a Concave Lens?

Answer 23

1) incident ray parallel to the axis refracts through lens, travels in line with the principal focus
2) incident ray passing through the lens towards the principal focus refracts through the lens and travels parallel to the axis.
3) incident ray passing through the centre of the lens carries on in the same direction.

Question 24

Concave lens and convex lens?

Answer 24

Question 25

What is a real image an example?

Answer 25

.where the light from an object comes together to form an image on a 'screen' - like image formed on eye's retina

Question 26

What is a virtual image and example?

Answer 26

.when the rays are diverging, light from object appears to be coming from a different place. . Mirror virtual image of your face because the object appears to be behind mirror. -magnifying lens

Question 27

How To describe an image properly, you need to say 3 things?

Answer 27

1) How big it is compared to the object; 2) upright or inverted (upside down) 3) real or virtual.

Question 28

How to Draw a Ray Diagram for an Image Through a Convex Lens?

Answer 28

1)Pick a point on the top of the object. Draw a ray going from the object to lens parallel to the axis of the lens 2) Draw another ray from the top of the object going right through the middle of the lens. 3) incident ray that's parallel to the axis is refracted through the principal focus (F) on other side of the lens.Draw a refracted ray passing through principal focus. 4) The ray passing through the middle of the lens doesn't bend 5) Mark where the rays meet (top of the image.) 6) Repeat the process for a point on the bottom of the object. When bottom of the object is on the axis, the bottom of the image is also on axis.

Question 29

How does Distance from the Lens Affects the Image? 2F, F and between

Answer 29

1) 2F= real, inverted image the same size as the object 2) Between F and 2F=real, inverted image bigger object, beyond 2F. 3) F= virtual image, right way up, bigger object, same side of the lens.

Question 30

How to Draw a Ray Diagram for an Image Through a Concave Lens?

Answer 30

1)Pick a point on the top of the object. Draw a ray going from the object to the lens parallel to the axis of the lens. 2) Draw another ray from the top of the object going right through the middle of the lens. 3) The incident ray that's parallel to axis is refracted so appears come from principal focus. Draw a ray from the principal focus,dotted before it reaches the lens. 4)Ray passing through the middle of the lens doesn't bend. 5) Mark where the refracted rays meet= top of the image. 6)Repeat the process for a point on the bottom object. bottom of the object is on the axis, bottom of the image is also on the axis. Concave Lenses Always Create…. Image? .concave lens always produces a virtual image.image is right way up, smaller than the object, on the same side of the lens as the object, no matter where object is.

Question 31

Magnifying Glasses Use Convex Lenses?

Answer 31

1)Job=creating a magnified virtual image. How= closer to the lens than the focal length. 2) virtual image (can't project) light rays don't actually come place where image appears to be. 4) magnification= image height/ object height

Question 32

Why does Colour and Transparency Depend on Absorbed Wavelengths?

Answer 32

Different objects absorb, transmit and reflect different wavelengths of light in different ways

Question 33

What is Opaque, what colours, what do they reflect/absorb?

Answer 33

1)objects that do not transmit light. 2)visible light waves hit them, absorb some wavelengths of light, reflect others. 2) colour opaque object depends wavelengths of light are most strongly reflected. reflecting wavelengths of light corresponding to that colour

Question 34

What is White and black what colours, what do they reflect/absorb?

Answer 34

-black= absorb all the wavelegnths of light -white= reflcts all the wavelengths of light

Question 35

What is Transparent and translucent what colours, what do they reflect/absorb?

Answer 35

1)Transparent (see-through) and translucent (partially see-through) 2) wavelengths light-not reflected or absorbed by an object= transparent. transmitted the light ‘see through’. 3)transmit some light but are not completely clear.

Question 36

Why do Colour Filters Only Let Through Particular Wavelengths?

Answer 36

1.white light passes through a coloured filter, all colours are absorbed except for the colour of the filter. E.g: orange filter transmits orange light but absorbs all the other colours. Only orange will show.

Question 37

What happens when an object appears black?

Answer 37

1)if it absorbs all the wavelengths of visible light. An object that appears blue in white light will appear black in red light. Red light contains no blue light for the object to reflect.

Question 38

How does the temperature of a given object change how much infraded radation is given off? what does it mean if an object has a contsant temperature? Does the colour of an object or the surafce amke a diffrence to wether the they absorb or emit more?

Answer 38

1)hotter object=more infrared radiation radiates 2)object hotter than its surroundings emits more IR radiation than it absorbs as it cools down. 3)object that's cooler than its surroundings absorbs more IR radiation than it emits as it warms up 4)Objects=constant temperature emit infrared radiation same rate that they are absorbing it. 5)Some colours and surfaces absorb and emit radiation better than others.

Question 39

What is a Leslie cube?

Answer 39

.hollow, watertight, metal cube made of aluminium, four vertical faces have different surfaces (matt black paint, matt white paint, shiny metal,dull metal).

Question 40

You Can Investigate IR Emission With a Leslie Cube? 5

Answer 40

1)Leslie cube heat-resistant mat. boiling water. 2)one minute=surfaces to heat 3)infrared detector measure intensity of infrared radiation emitted from each surface. 4)detector same distance each surface for each reading- reaptable and fair 5) matt black emits the most, shiny black, white, shiny matellic

Question 41

What can you also investigate with a Leslie cube and how? 3

Answer 41

1)absorption depends on surfaces. 2)stick ball the back of two different surfaces with wax 3)which one falls off first when surfaces placed equal distances Bunsen burner

Question 42

What is intensity?

Answer 42

.power per unit area, i.e. how much energy transferred to a given area in a certain amount of time.

Question 43

What are perfect black bodies?

Answer 43

1)perfect black body= object that absorbs all of the radiation that hits it. No radiation is reflected or transmitted. 2)All objects emit electromagnetic radiation due energy in their thermal energy stores=range wavelengths frequencies. Perfect black bodies= best possible emitters of radiation.

Question 44

What impacts intensity and distribution of wavelengths emitted by an object?

Answer 44

1)object's temperature. temperature object increases, intensity of every emitted wavelength increases.

Question 45

What impacts wavelengths?

Answer 45

-intensity increases rapidly for shorter wavelengths -very hot objects realise short wavelengths that's why very hot objects produce visible light

Question 46

How does radiation keep the earths temperature constant? How does the atmosphere change the earths temperature?

Answer 46

1) temperature Earth depends on amount of radiation it reflects, absorbs and emits. 2) day: lots of radiation transferred to Earth from the Sun absorbed.+ increase 3) night=less radiation absorbed than emitted,=decrease 4) temperature constant. 1)Changes atmosphere=changes Earth's 2)absorb more radiation without emitting the same amount,overall temp rise until absorption and emission are equal again.

Question 47

What reflects and absorbs radiation? 3

Answer 47

.atmosphere, clouds, earth surface

Question 48

How do sound waves travel? Where do soundwaves travel the fatsest from? 3 how do sound waves travel through a soild? Can sound waves travel through space?

Answer 48

1)Sound waves= vibrations passes medium compressions,rarefactions 2) Sound travels faster solids, liquids, gases. 3)sound wave travels through solid the particles in solid to vibrate. 4) Sound can't travel in space- vacuum (there are no particles to move or vibrate).

Question 49

How do your ears process sound?

Answer 49

1.ear, sound waves cause the ear drum and other parts to vibrate which causes the sensation of sound. 2.conversion of sound waves to vibrations of solids works over a limited frequency range. -This restricts the limits of human hearing. 20HZ 20KHZ

Question 50

What are echos?

Answer 50

reflected sound waves.

Question 51

How do Sound Waves Can Reflect and Refract? reflected- hard and flat refracts- enters another medium

Answer 51

1)Sound waves reflected by hard flat surfaces. 2) refract enter different media. denser material =speed up. -wave travels different medium, wavelength changes frequency remains the same = speed change

Question 52

What is an ultra sound? what frequency do they produce?

Answer 52

.Electrical devices=produce electrical oscillations range frequencies. converted into mechanical vibrations =produce sound waves beyond the range of human hearing (above 20 000 Hz).

Question 53

What is a partial reflection?

Answer 53

wave passes one medium into another, some wave is reflected off the boundary between two media some is transmitted (and refracted).

Question 54

Why do Ultrasound Waves Get Partially Reflected at Boundaries?

Answer 54

1)partial reflection point pulse ultrasound at object, and wherever boundaries between ultrasound gets reflected back. 2)time it takes reflections to reach a detector measure far away the boundary is

Question 55

How Ultrasound is Useful in 2 ways?

Answer 55

1)Medical imaging=ultrasound waves pass body, whenever they reach a boundary between two different media wave reflected back, detected. 2)exact timing, distribution echoes processed computer 2)Industrial imagine=finding flaws materials, waves entering a material reflected, flaw such wave will be reflected sooner.

Question 56

What is echo sounding and how is it used?

Answer 56

-Echo sounding uses high frequency sound waves (ultrasound). -used by boats and submarines to find the depth of water -distance = speed x time

Question 57

What happens when a wave reaches a boundary (2)?

Answer 57

1) Waves different properties depending material travelling through: 2)completely reflected or partially reflected continue travelling same direction different speed, -be refracted or absorbed

Question 58

How can Waves Can Be Used to Detect and Explore, what waves do you use 2?

Answer 58

.-properties and paths waves through structures=properties of structure that you can't see by eye. ultrasound and seismic waves.

Question 59

What are seismometers and Seismologists?

Answer 59

.seismometers=Detects seismic waves .Seismologists=work out the time it takes for the shock waves to reach each seismometer.

Question 60

How do Earthquakes and Explosions Cause Seismic Waves+process?

Answer 60

1) seismic waves reach boundary between different layers of material Earth, some waves will absorbed and some refracted. 2) waves are refracted change speed= curved path. -wave speed changes abruptly, path has a kink.

Question 61

What are the two seismic waves?

Answer 61

.P waves and S waves

Question 62

What is the differences between P waves and S waves? 4

Answer 62

.P-waves can Travel through the Earth's Core, S-waves can't .p waves= longitudinal, S waves= transverse .p waves travel through solids and liquids, S waves only soilds .p waves=fastest, slower= p waves

Question 63

How has observing seismic waves helped?

Answer 63

-observing how seismic waves are absorbed and refracted, properties Earth structural change.

Question 64

What can medium radio waves do?

Answer 64

Reflect from the ionosphere depending on atmospheric conditions and the time of the day.

Question 65

What radio waves used for TV and radio transmissions, how does it work?

Answer 65

-Short wavelengths= get reception must be direct sight of transmitter signal doesn’t bend or travel far through buildings

Question 66

What are short radio wave signals? What is the ionosphere?

Answer 66

-received long distances from the transmitter -reflected from ionosphere- electrically charged layer in earths upper atmosphere

Question 67

What is the universe made up of?

Answer 67

Dark matter dark energy (unknown substance) holding galaxy together not emit electromagnetic radiation.

Question 68

What is dark energy responsible?

Answer 68

Accelerated expansion of the universe not completely known.

Question 69

How can you produce radio waves using AC? 3

Answer 69

-electrons oscillates to create radio waves= transmitter 1)transmitted radio waves reach a receiver radio waves absorbed 2)energy carried by the waves is transffered electrons in the material of the receiver 3)energy causes electrons to oscillate=generates AC

Question 70

Long wave radio transmitted along way why?

Answer 70

-long wave length diffract (bend) around carried surfaces of the earths. -diffract around hills into tunnels. -received even if receiver isn’t in sight of transmitter

Question 71

Example of short wave radio?

Answer 71

Bluetooth send data over short distances between devices without wires

Question 72

Microwave ovens also use microwaves how?

Answer 72

1) microwaves absorbed by water molecules in food 2) microwaves penetrate into food before being absorbed, transmitted energy carrying water molecules in food, water heats up 3) water molecules, transfer this energy to the rest of the molecules in the food by heating

Question 73

Infrared radiation 3 uses?

Answer 73

1)infrared cameras=monitor temperature camera. Detects infrared radiation->electrical signals hotter=brighter. 2)Food can be cooked using infrared radiation temperature food 3)electrical heaters contain long piece of wire, heats up current and flows through it. thermal energy stores of the objects,

Question 74

What are electromagnetic waves and what are they made up of?

Answer 74

-alternating currents made up of oscillating charges produce Oscillating, electric fields

Question 75

Frequency of waves produced equals?

Answer 75

Frequency of the AC

Question 76

Electromagnetic waves and can they travel through the vacuum of space?

Answer 76

Transverse waves transfer energy source to the absorber can travel through vacuum of space

Question 77

All the electromagnetic waves?

Answer 77

Question 78

Refracted?

Answer 78

Waves that cross boundary between materials meaning angle changes direction

Question 79

Why wave slows or faster Crossing Way boundaries? (2)

Answer 79

.slows (denser)= bend towards the normal .faster (less dense)= bend away from the normal

Question 80

Does the frequency change when refracted?

Answer 80

No

Question 81

Wave travelling along normal it will…?

Answer 81

Change speed, not refracted

Question 82

What can gamma radiation jobs? 1

Answer 82

Medical tracers- gamma emitting source Injected into patient=progress controlled around body -because pass out through the body to be dejected

Question 83

Is EM radiation harmful?

Answer 83

-Effects of each type of radiation based on how much energy waves transfer how ionising they are

Question 84

Low frequency?

Answer 84

Don’t transfer much energy and mostly passes through soft tissue without being absorbed e.g radio waves

Question 85

High-frequency

Answer 85

Transfer a lot of energy causes a lot of damage e.g. x-rays

Question 86

Harmful UV radiation 3 ways?

Answer 86

.Damages surface cells=sunburn, skin ages prematurely .Skin cancer and blindness

Question 87

Harmful x-rays and gamma rays?

Answer 87

Ionising radiation can carry enough energy to knock electrons of atoms causes gene mutation and cell destruction and cancer

Question 88

How do you see inside different parts of the body? 2 and 1 risk

Answer 88

CT scan=x-rays -computer to build a picture inside of parts body -likely to suffer radiation depending parts of the body

Question 89

Radiation dose?

Answer 89

Risk measures harm from body being exposed to radiation

Question 90

Risks of radiation depends on?

Answer 90

Depends on the amount of radiation, absorbed and how harmful the type of radiation is

Question 91

Sievert to millisivert?

Answer 91

1000 Millisievert= 1 Sievert

Question 92

Method to different materials reflecting light by different amounts? 4

Answer 92

1. Piece of paper draw the glass block which is the boundary draw the normal line at 90 2. Shine light at object using a ray box to normal point adjusting till you see a reflected ray= trace, incoming, and reflected beams 3. protractor-measure angle of incidence and angle reflection record values note, brightness reflected ray 4. Repeat with a range of objects. Glass perfex. It is the exact same

Question 93

Mirrors and smooth surfaces, do what with reflecting?

Answer 93

Play reflection, reflected ray finned, and bright as the incident ray

Question 94

Rough surfaces?

Answer 94

Diffuse reflection, causes reflective beam to be wider and dimmer

Question 95

How are microwaves used by satellites? 4

Answer 95

1.Used=passes easily through earths atmosphere 2. TV signal from transmitter, transmitted into space. 3. Picked by satellite receiver dish, transmits signals back earth different direction. amplified 4. Received by satellite dish ground.

Question 96

How to construct a ray diagram for refracted light ray?

Answer 96

1. boundary between two materials, normal 90° to the boundary. 2. Draw incident ray meets normal- protractor 3. Draw refracted Ray other side boundary. -optically denser than first=refracted ray towards normal angle between infracted and normal smaller angle of incidence. -less optically dense= refracted away from normal angle= refraction larger angle then incidence.

Question 97

What environment is needed to test rays of light?

Answer 97

Dim room, so you can clearly see them

Question 98

What are boundaries?

Answer 98

Different substances that reflect light different amounts

Question 99

How do you fibre optic cables work? Why does light refract when traveling through the cables?

Answer 99

(Optic fibres) plastic fibre and visible light=data over distance 1. refract light bounced back and forth 2. Because: Light is not easily, absorbed, scattered when travelling among fibre.

Question 100

How does ultraviolet create a bulb 2 positives? What are the two uses and how?

Answer 100

1)Fluorescent light-generate UV radiation, absorbed reemitted, visible, light 2)energy efficient long periods of time .Security pens=glow invisible light. . Suntans=Too much UV exposure can cause cancer

Question 101

How do X-rays work?

Answer 101

Radiographs in hospital easily pass flesh, not through bones. Amount of radiation. Absorbed makes an x-ray image.

Question 102

What radiation do you use for radiographers, what do they do? How does this work? What protection methods are there from the rays? 3

Answer 102

1)X-rays and gamma rays=treat cancer. High doses of rays kill all living cells. 2)Carefully directed to cancer cells avoid killing healthy cells 3)aprons, lead screen, and leave room exposure to minimum

Question 103

What is the refractive index?

Answer 103

Refractive= light changes direction -optical density= how quickly light passes through Wavelength and speed are directly proportional

Question 104

Concave and conveys diagrams?

Answer 104

Convex= real or virtual Concave= virtual