# P1 Physics

• Created by: wafflypig
• Created on: 02-04-16 11:22
What is wave amplitude?
The height from the axis to peak/axis to trough
1 of 134
What is wavelength?
The distance from one peak to the next
2 of 134
What is a transverse wave?
The vibrations travel at 90 degrees to the direction of travel of the wave
3 of 134
What is a longitudinal wave?
The vibrations travel along in the same direction as the way the way is travelling
4 of 134
Give 2 examples of a transverse wave
Visible light, X-rays, S-waves and any other EM wave
5 of 134
What is the geocentric model?
The old theory that earth is the center of the solar system and everything orbits around earth
6 of 134
What is the heliocentric model?
The now accepted theory that the sun is the center of the solar system and everything orbits the sun
7 of 134
Who first queried the geocentric model?
Corpenicus
8 of 134
How did Gallileo provide evidence to disprove the geocentric model?
He watched 3 "stars" for week. For the first three days the "stars" moved around Jupiter. This means they were moons orbiting Jupiter - proving not everything orbits earth. After a week a fourth appeared.
9 of 134
What kind of telescope did Galileo use?
A refracting telescope
10 of 134
In what shape do planets orbit the sun?
Elliptical
11 of 134
What is a real image?
Where light comes together to form a physical image on a screen
12 of 134
What is a virtual image?
When rays are diverging so the light looks like it's coming from a different place
13 of 134
What image is produced when you look in a mirror?
Virtual
14 of 134
What image is produced when you look through a magnifying glass?
Virtual
15 of 134
When does light change direction in refraction?
When it enters a medium with a different density at an angle other than the normal.
16 of 134
What is refraction?
When light changes speed, and usually direction when entering a medium with a different density
17 of 134
What is reflection?
When light rays hit a different medium and some of its energy is bounced back (reflected)
18 of 134
Angle of incidence =....
Angle of reflection
19 of 134
What is wave frequency?
The number of complete waves passing a point per second - measured in Hertz (Hz)
20 of 134
What are converging used for?
To focus light (and correct long-sightedness)
21 of 134
What is focal length?
The distance between the center of the lens and its focal point
22 of 134
What is image distance?
The distance between the center of the lens and the image produced on the screen
23 of 134
What is object distance?
The distance between the center of the lens and the object that light is reflecting off
24 of 134
What is a focal point?
The point at which all the light rays that were travelling parallel to the optical axis come together
25 of 134
Where is the optical axis?
Horizontally through the center of the lens
26 of 134
How would you find the focal length of a lens?
Put an object on one side of the lens, and move the lens back and forth until a clear image is produced on the screen. Measure the distance between the lens and screen (focal length).
27 of 134
How many lenses does a refracting telescope use?
2
28 of 134
What do reflecting telescopes use?
2 mirrors and converging eyepiece lens
29 of 134
Ritter
30 of 134
Herschel
31 of 134
How did Ritter discover ultraviolet radiation?
By noticing it took the longest time for silver chloride to go from white to black just past violet on the spectrum
32 of 134
How did Herschel discover infrared radiation?
He noticed that the part of the spectrum with the highest temperature was just past red
33 of 134
What is the EM spectrum in order?
Radio, microwaves, infrared, visible light, ultraviolet, xray, gamma
34 of 134
True or false, all EM waves are transverse and travel at the same speed in a vacuum
True
35 of 134
What decreases as you move from left to right on the EM spectrum?
wavelength
36 of 134
What 2 things increase as you from left to right on the EM spectrum?
Danger and frequency
37 of 134
What do the properties of EM waves depend on?
Frequency
38 of 134
What are the dangers of microwaves?
Heat human body cells
39 of 134
What are the dangers of infrared radiation?
Skin burns
40 of 134
What are the dangers of UV radiation?
Skin cancer and eye damage
41 of 134
What are the dangers of Xrays/Gamma rays?
Cell mutations and cancer
42 of 134
True or false, the higher the frequency, the higher the danger
True
43 of 134
Give a use of radio waves
44 of 134
Give a use of microwaves
Satellite communication and mobile phones. Can be used to heat food at a different wavelength
45 of 134
What is the ionosphere?
The uppermost, charged layer of earth's atmosphere
46 of 134
Give 3 uses of infrared radiation
Thermal imaging/night vision/transmit data/cooking/remote controls/security systems
47 of 134
How do optical fibers transmit data?
The infrared waves are repeatedly reflected off the inner walls of the wire over a long distance
48 of 134
Give a use of visible light
Vision/cameras
49 of 134
Give a use for UV radiation
Detect forged bank notes by looking at fluorescence
50 of 134
Give a use of X rays
Look inside the body/objects (eg in a hospital or airport)
51 of 134
The treatment of cancer using gamma rays
52 of 134
Give 2 uses of gamma rays
Sterilising food and surgical equipment/treating cancer
53 of 134
What are the three types of ionising radiation?
Alpha, beta and gamma
54 of 134
How do gamma rays lead to cancer?
The exposure causes ionisation of the cells randomly which caused cancer
55 of 134
How can we see planets with the naked eye?
They reflect light from the sun into our eyes
56 of 134
What is 1 lightyear?
The distance light travels in a vacuum in one year
57 of 134
What is a vacuum?
An area with no air in it
58 of 134
What galaxy are we in?
Milky Way
59 of 134
What is a galaxy?
A collection of billions of stars
60 of 134
What is the Universe?
A collection of billions of galaxies
61 of 134
What is SETI?
Search for ExtraTerrestrial Life
62 of 134
How does SETI do what it does?
Looks for meaningful signals in the noise of the radio waves in space
63 of 134
Give 2 ways the surface of a planet can be analysed
Robot/Lander/Probe
64 of 134
Why is it better to have a telescope in space?
Atmosphere distorts images and light pollution from earth
65 of 134
Give an example of a telescope in space
Hubble
66 of 134
What are the problems with having space telescopes?
Expensive and hard to maintain
67 of 134
What is a spectrometer?
A tool used to analyse light given out by stars
68 of 134
Why do absorption lines happen?
Because the light at those wavelengths has been absorbed by specific elements
69 of 134
Give a use of a spectrometer
To prove red shift
70 of 134
What is a nebula?
Clouds of dust and gas, the first stage in the life cycle of a star
71 of 134
What causes a nebula to come together and form a solid block?
Gravity. The gravitational energy is transferred to thermal energy
72 of 134
What is a main sequence star?
The main part of a star's life where thermonuclear fusion happens and helium nuclei are produced. This is a long stable period
73 of 134
What happens to small stars?
They go to a planetary nebula to a white dwarf
74 of 134
What happens to big stars?
Supernova, neutron star(or black hole)
75 of 134
What is a planetary nebula?
When a main sequence star ejects its outer layer of dust and gases
76 of 134
What is a white dwarf?
A hot, dense solid core
77 of 134
What is a supernova?
When so much fusion happens that the main sequence star explodes
78 of 134
What is a neutron star?
A very, very dense solid core
79 of 134
Give three pieces of evidence that support the Big Bang Theory
CMBR, red shift
80 of 134
What is the CMBR?
Cosmic Microwave Background Radiation is left over radiation from the big bang
81 of 134
What is red shift?
The change in observed wavelength due to galaxies moving away from each other, visible in spectral absorption lines
82 of 134
How long ago was the big bang?
13.7 billion years ago
83 of 134
What is ultrasound?
Sound with frequency over 20,000Hz
84 of 134
What is infrasound?
Sound with frequencies under 20Hz
85 of 134
What is 1Hz
1 wave passing a point per second
86 of 134
Give 2 uses of ultrasound
Sonar, pre-natal scanning
87 of 134
Give a use of infrasound
Animal communication
88 of 134
How does sonar work?
A computer measures the time between an ultrasound wave leaving the ship and returning (reflected from the media with a different density)
89 of 134
Why is it not a good idea to use X rays for prenatal scanning?
X rays cause could cause cell mutations in the foetus which might kill it
90 of 134
Speed = .....
Distance/Time
91 of 134
Give the structure of earth from inside to out
Inner core, outer core, mantle, crust
92 of 134
Give the states of each part of Earth's structure
Inner core = solid, outer core = liquid mantle = very viscous liquid, crust = solid
93 of 134
Give the properties of an S wave
Transverse, travel slower than P waves, only travel through solids
94 of 134
Give the properties of a P wave
Longitudinal, travel fast, do less damage, get there before S waves, travel through solids and liquids
95 of 134
How can you calculate the epicenter of an earthquake using a seismograph?
Find the time difference between the 2 tremors (P and S wave). Use the time difference as a radius for three circles on a map. The point where all 3 circles cross is the epicentre
96 of 134
Why can't you just use 2 circles to find the epicenter?
They will cross at 2 places
97 of 134
Where do you plot the center of the circles?
At each seismometer
98 of 134
What is current?
The rate of flow of charge around an electrical circuit
99 of 134
What is voltage?
An electrical pressure that makes current flow
100 of 134
Even though electrons are negatively charged, we still say current flows from +ve to -ve because we thought this long ago: true or false
True. They actually flow from -ve to +ve
101 of 134
What is electrical power?
The energy transferred per second
102 of 134
What is a CRO?
Measures AC and DC current
103 of 134
What is DC current?
Direct Current that continually flows in one direction only
104 of 134
What is AC current?
Alternating Current constantly changes direction
105 of 134
What type of current do batteries supply?
DC
106 of 134
How can you induce a voltage?
Move a magnet inside a metal coil
107 of 134
What 4 factors affect the size of the voltage and current induced with a magnet in a coil?
Strength of the magnet, number of turns in the coil, area of the coil and speed of the movement
108 of 134
Give 3 examples of non-renewable energy sources
Coal, nuclear fuels, oil, gases
109 of 134
What are the 3 fossil fuels?
Coal, oil and natural gas
110 of 134
What are 3 things environmentally problematic when it comes to non-renewable energy sources?
Release of CO2 (=greenhouse effect=global warming). Mining ruins the landscape. Burning coal causes acid rain by releasing SO2. Nuclear power has risk of disaster. Dangerous nuclear waste. Oil spills
111 of 134
What is a renewable energy source?
An energy source that will never run out
112 of 134
How does a hydroelectric dam work?
Rainwater is let through a dam, turning a turbine (GPE to KE) to spin a magnet in a generator
113 of 134
Habitats lost but produces lots of electricity
114 of 134
Give 2 other ways water can be used to generate electricty
Wave power, tidal barrages
115 of 134
Give 3 other ways electricity can be generated
Wind power, geothermal and solar
116 of 134
Give 4 things to consider when setting up a power station
Location/Running costs/Set-up time/Set-up costs/Reliability/Environment
117 of 134
True or false, there are less coils on a step-up transformer?
False
118 of 134
Why is it important for voltage to be stepped up?
So less is wasted as heat energy as it is transferred around the national grid. This increases efficiency
119 of 134
Give 2 issues with transmitting this much energy in the National Grid
Power losses are still high (even with transformers), high voltage is a risk to humans (fly a kite into it = electrocution), living near a power line may cause leukemia.
120 of 134
What is the purpose of a step down transformer?
It reduces to the voltage to a safe level for use in homes (240V)
121 of 134
Give 4 ways you can save money on energy bills
Loft insulation, cavity wall insulation, thick curtains, foil behind radiators, double glazing and hot water tank jacket
122 of 134
What are the 10 types of energy?
Kinetic, magnetic, light, sound, thermal, nuclear, chemical, GPE, elastic potential, electrical
123 of 134
What does conservation of energy say?
Energy can never be created nor destroyed - only transferred
124 of 134
What kind of energy do batteries use?
Chemical
125 of 134
What is efficiency?
The proportion of energy input that is transferred into useful energy
126 of 134
Which energy on the EM spectrum is mostly absorbed by the atmosphere?
Infrared (and some ultraviolet)
127 of 134
Give 2 energies on the EM spectrum that are not absorbed by the atmosphere
Visible light (well, 10% is absorbed). Microwaves
128 of 134
Why is it a good idea to paint the container that a motor is in black?
It emits more heat energy after it has been absorbed. This means the motor will not overheat.
129 of 134
What is Leslie's Cube?
Has alternating sides made of shiny and dark material. Thermometer is placed just by each side. The ones near the black sides will show temperature increase fastest and greatest.
130 of 134
Which type of current do step-up and step-down transformers transform?
AC only.
131 of 134
Which has more primary windings, step-up or step-down transformer?
Step-down transformer
132 of 134
What does a step-up transformer do to voltage?
Change it from primary to secondary voltage. The step-down transformer does the opposite.
133 of 134
Give 3 things that should be considered when setting up a new power plant
Environment (will it destroy habitats, scenery etc?). Reliability (will it work?). Set-up costs (do you have the money?). Set-up time (Gas is quick). Running costs (do you have the money for maintence + fuel?). Location issues (pop dens=Bopahl)
134 of 134

## Other cards in this set

### Card 2

#### Front

What is wavelength?

#### Back

The distance from one peak to the next

### Card 3

#### Front

What is a transverse wave?

### Card 4

#### Front

What is a longitudinal wave?

### Card 5

#### Front

Give 2 examples of a transverse wave