Physics Revision Flashcards
(228 cards)
1
Q
Energy
A
something that cannot be created or destroyed, only transferred from one source to another
2
Q
Nuclear Energy
A
energy inside the nucleus of an atom
3
Q
Elastic Potential Energy
A
energy inside things that can stretch
E = 0.5 x k x e^2
4
Q
Chemical Energy
A
energy from chemical reactions
5
Q
Gravitational Potential Energy
A
energy in gravity
6
Q
Kinetic Energy
A
energy in things that move, such as people’s bodies and also sound
KE=1/2mv^2
7
Q
Magnetic Energy
A
energy in magnets
8
Q
Thermal Energy
A
energy of heat
9
Q
Open System
A
systems which interact with their environment, so that energy or mass can be added or removed from them
10
Q
Closed System
A
an isolated system in which no energy transfers take place out of or into the energy system
11
Q
Mechanical Transfer
A
happens in things like cycling
12
Q
Electrical Transfer
A
happens in things like static electricity
13
Q
Transfer by Heating
A
happens in things like boiling eggs
14
Q
Transfer Through Radiation
A
happens in things like sound waves
15
Q
Work Done
A
force x distance
energy transferred
16
Q
Efficiency
A
a measure of how good a device is at changing energy from one form to another
17
Q
Power
A
energy transferred in a given time
power = energy transferred/time taken
18
Q
Conduction
A
transfer between particles in a solid
19
Q
Conductor
A
a substance that conducts heat, such as a lightening rod on the side of a building
20
Q
Conductivity
A
the power of heat conduction
21
Q
Insulator
A
a bad conductor whose particles are too far apart to allow energy to flow between them, such as liquids, gasses and vacuums
22
Q
Density
A
mass per unit volume
23
Q
Melting
A
transfer from solids to liquids
24
Q
Freezing
A
transfer from liquids to solids
25
Boiling
transfer from liquids to gasses
26
Condensing
transfer from gasses to liquids
27
Temperature
a measure of the average kinetic energy of the particles in an object
28
Internal Energy
the sum of all the kinetic energy the individual particles have from moving relative to each other and the potential energy that individual particles have because of their positions relative to each other in a substance
29
Unstable
an element becomes unstable if there are too many protons or neutrons, in an attempt to stablise itself, it omits radioactivity, decaying
30
Background Radiation
a type of relation that is always present around us, but with very low doses, which is safe, including underground rocks, food, cosmic rays from the sun and industrial uses
31
Radius of an atom
1x10^-10
32
Ionisation
any process by which atoms become charged
33
Irradiation
when an object is exposed to ionising radiation and the object does not become radioactive
34
Contamination
the unwanted presence of materials containing radioactive atoms on other materials, due to the decay of contaminating atoms
35
Decay
where a radioactive nucleus gives out alpha, beta or gamma particles
36
Alpha Decay
releases 2 protons and 2 neutrons
37
Beta Decay
gains a proton
38
Alpha Particle
the same as a helium nucleus
39
Beta Particle
the same as a high-energy electron
40
Alpha
two protons, two neutrons, stopped by a sheet of paper, very high ionising ability, slow speed, positive charge
41
Beta
electron, medium ionising ability, stopped by 5mm aluminium, negative charge, fast
42
Gamma
electromagnetic wave, least ionising, stopped by thick concrete, no charge, travels at the speed of light
43
Speed of Light
3x10^8mps
44
Half Life
the time it takes for the count rate to halve
45
Activity
the number of unstable atoms that decay per second in a radioactive source, measured in Bacquerei
46
Net Decline
the overall amount that the activity of a source has fallen in a period of time
47
Gamma Knife
used to treat cancers, small doses are targeted at the tumour from a moveable box, concentrated on the tumour
48
Radioactive Tracers
used in medicine to trace the flow of a substance through an organ
49
Radioactive Implants
used to destroy cancer cells in some tumours
50
Nuclear Fission
involves isotopes being split up, releasing energy
51
Nuclear Fusion
involves isotopes being joined together, releasing energy
52
Induced Nuclear Fission
occurs when a stable isotope is struck by a neutron, where the isotope absorbs the neutron, becomes unstable and splits into smaller fragments, releasing neutrons and energy
53
Nuclear Bombs
uncontrolled fission reactions
54
Chain Reaction
where one fission reaction goes on to cause several more
55
Spontaneous Nuclear Fission
roughly the same as induced, but happens without a neutron being absorbed
56
Static Charge
where an insulator is charged up by friction, causing electrons to either be rubbed onto or rubbed off the object causing them to be charged, only the negative charge move
57
Earthing
the process in which electric energy is instantly discharged directly to the earth through a low resistance wire, e.g. lightening wires, reducing risk of electric shock as energy is transferred down the wire quicker than it could anyone
58
Pipe Earthing
when electricity is sent down a pipe to the ground
59
Plate Earthing
when electricity is sent into an underground plate
60
Series Circuit
increasing voltage makes lights brighter, adding an extra bulb makes lights dimmer, unscrewing one breaks the circuit, current stays the same, potential difference is shared
61
Parallel Circuit
increasing voltage makes bulbs brighter, adding an extra bulb has little effect, unscrewing one bulb has no effect on other bulbs, current is shared, potential difference stays the same
62
Ammeter
measures current, must be in series with the component you are measuring
63
Voltmeter
measures potential difference, must be in parallel with the component you are measuring
64
Current
rate of flow of electrons
65
Conventional Current
flows from positive to negative, whilst electrons flow from negative to positive
66
Energy Transferred
E = VxQ
67
Potential Difference
V = IxR
68
Ohm's Law
current is directly proportional to voltage when the temperature of the conductor is constant
69
Light Dependent Resistor
resistance decreases when light intensity increases
70
Thermistor
resistance decreases when temperature increases
71
Direct Current
current from cells and batteries which always flows in the same direction
72
Alternating Current
current from the mains, which is constantly changing direction
73
Oscilloscope
allows a visual representation of electrical signals, such as sound signals or electrical signals from someone's heart
74
Amplitude
the top of a wave on an oscilloscope
75
Frequency
amount of waves per second
76
Period
time for one wave
77
Fuse
a thin piece of wire that gets hot and blows if too high a current flows, breaking the circuit and preventing fires
78
Residual Current Circuit Breaker (RCCB)/Residual Current Device (RCD)
resettable fuses, usually found in homes, which are more sensible than plug fuses
79
Neutral Wire
the blue wire, goes on the left
80
Live Wire
the brown wire, goes on the right
81
Earth Wire
the yellow and green wire, goes through the middle, connects to the metal case of an appliance, occurs when the current flows down from the earth wire instead of through you if you touch it, prevents electric shock
82
Plugs
contains the cable, cable grip, three wires and a fuse, made of copper because it is flexible, brass because it's an alloy, strong and durable, copper because it is a good conductor, plastic because it is an insulating, hence a casing
83
Double Insulation
improves safety by making sure an item that has two plastic cases without any wires touching the case, meaning the case cannot become live, because plastic does not conduct electricity, meaning that if one layer of insulation is damaged, the appliance is still safe for use
84
Power
P = I x A x V
P = I x A^2 x R
P = E/t
85
National Grid
a system of transformers and cables
86
Step-up Transformer
increases the potential difference, which reduces energy loss in transmission cells
87
Step-down Transformer
reduce the potential difference before the electricity crosses to homes
88
Scalar Quantity
a quantity that has magnitude but no specific direction
89
Vector Quantity
a quantity that has magnitude and a specific direction
90
Resultant Force
the net force acting, the sum of all forces acting on the object
91
Contact Force
something like air resistance, which involves contact
92
Non-Contact Force
something like gravity, which doesn't involve contact
93
Parrallelogram of Forces
used to work out resultant forces where forces don't just go up and down
94
Equilibrium
when forces have no overall turning effect, meaning the resultant force is often zero
95
Force
N = J/m
96
Gravity
N/kg = N/kg
97
Hooke's Law
states that the extension of a spring is directly proportionate to the force applied, provided its limit of proportionality is not extended
98
Spring Constant
K = F/e
99
Elastic Limit
point where object has stretched more than expected and can no longer return to its normal shape
100
Speed
how fast something is going
distance/time
101
Velocity
speed and direction
distance/time
102
Isotope
atoms of the same element with a different number of neutrons
103
Energy Levels
electrons are arranged at different distances from the nucleus called energy levels or shells
104
Sieverts
the unit for measuring radiation doses
105
Particle Physicist
someone who studies the part of physics that relates to particles
106
Geiger Counter
used to measure the amount of radioactivity in the air
107
Distance
a scalar quality that describes how far an object moves
108
Displacement
includes both the distance an object moves, measured in a straight line form the start point to the finish line, and the direction of that straight line, a vector quality
109
Average Walking Speed
1.5 m/s
110
Average Running Speed
3 m/s
111
Average Cycling Speed
6 m/s
112
Average Train Speed
100 km/h
113
Average Plane Speed
900 km/h
114
Acceleration
measured in m/s^2
a = v/t
115
Uniform Acceleration
(final velocity)^2 - initial velocity)^2 = 2 x acceleration x distance
v^2 - u^2 = 2as
116
Ohmic
where resistance remains constant as current changes
117
Particle Acceleration
apparatus for accelerating subatomic particles
118
Van de Graaff
generator that uses an electric belt to accumulate charge
119
Ion
a charged atom
120
Concrete Shield
protective barrier to stop objects outside getting contaminated
121
Control Rods
absorbs stray neutrons, making sure the reaction stays under control, can be moved in and out depending on how many neutrons need to be absorbed
122
Fuel Rods
made of a form of Uranium
123
Heat Exchanger
full of steam which falls down and becomes water as it cools
124
Pump
controls the amount of water in the reactor at any one time
125
Turbines
driven by steam heated by the nuclear power, which condenses into water and goes through the reactor all over again
126
Steel Vessels
contain the stuff for the nuclear reactor, steel to make sure contamination doesn't happen
127
Reactor Core
the most important part of the reactor, where the nuclear bit happens
128
Pressuriser
regulates coolant pressure in the nuclear reactor
129
Newton's First Law
states that if forces are balanced on an object, it either does nothing or continues to do what it's doing
130
Newton's Second Law
states that if you increase forces, something goes faster
Resultant Force = mass x acceleration
131
Newton's Third Law
states that all forces have an equal and opposite force
132
Inertia
a tendency of an object to remain unchanged, or continue in an existing state
133
Terminal Velocity
acceleration of a falling object acted on only by gravity
0
134
Reaction Time
0.2 - 0.9 seconds
135
Conservation of Momentum
in a closed system, the total momentum before an event is equal to the total momentum after the event
136
Earth's gravitational field strength
9.8N/kg
137
Stopping Distance
thinking distance + braking distance
138
Thinking Distance
stopping distance - braking distance
139
Braking Distance
stopping distance - thinking distance
140
Crumple Zone
part of a car that increases the impact time, lessening the impact force
141
Kilo
10^3
142
milli
10^-3
143
Mega
10^6
144
micro
10^-6
145
Giga
10^9
146
Nano
10^-9
147
Tachographs
devices in long-distance vehicles that monitor driving time, speed and distance
148
Neutrino
a particle able to travel faster than the speed of light
149
Systematic Error
an error that causes the same problem to all pieces of data such as something causing every piece of data to be 30 seconds off
150
Personal Error
an error caused by a person's habits, a type of systematic error
151
Random Error
an error that affects only one result, such as misreading the scale once
152
Ultrasound
sound above the maximum frequency that humans can hear
20000Hz
153
Pascal
N/m^2
154
Pressure
Force / Area
155
Fluid
Liquid or gas
156
Pressure due to a column of liquid
Pressure = column height x density of liquid x gravitational field strength
157
Pascal vases
vases that show how liquid flows until the pressure along the same horizontal level is constant
158
Atmosphere
a thin layer relative to the size of the Earth around the Earth
159
Atmospheric Pressure
air molecules colliding with a surface
160
Upthrust
the force on an object in a fluid, that is equal to the weight of the fluid displaced
volume of body submerged x density of liquid x acceleration due to gravity
161
Boiling Point
the point at which vapour pressure equals atmospheric pressure
162
Vapour Pressure
the pressure exerted by the gas when the amount of particles leaving the liquid equals the amount entering the liquid
163
Earth's atmospheric pressure
101325Pa
164
Gears
rotating wheels with teeth that interlock with each other used to transmit and often multiply rotational forces, hence they act in a similar way to levers
165
Centre of Mass
the point at which the mass of the body may be thought to be concentrated
166
Driven Gear
gear that is moved
167
Driving Gear
gear that does the moving
168
Idle Gear
gear between driving and driven
169
Plumb Line
mass on a string that hangs vertically
170
Period
time taken for a pendulum to swing
171
Point of Balance
must be directly above the centre of mass
172
Pivot
the point at ninety degrees to the force which the turning happens around
173
Newton metres
measurement for moments
174
Moment
turning effect of a force
force x distance
175
Total clockwise motion
same as total anticlockwise motion
176
Lever
something to amplify the force, meaning it exerts a greater force than that applied by the effort
177
Gear
something to change the force or rotational speed of a system
178
Effort
the force exerted on the lever
179
Load
the amount being moved
180
Principle of Moments
the moment of any force is equal to the algebraic sum of the moments of the components of that force
181
Stability
a measure of the body's ability to maintain its original position
182
Vibrations
a constant repeated back and forth or up and down motion
183
Wave
a series of disturbances that are the same distance from each other and transfer energy from one place to another
184
Mechanical Wave
waves which need a medium (e.g. sound waves, water waves)
185
Electromagnetic Wave
waves which do not need a medium (e.g. light waves)
186
Transverse Wave
a wave where the vibration are perpendicular to the direction of the energy transfer
187
Longitudinal Wave
a wave where the vibrations are parallel to the direction of energy transfer
188
Peak
the top of a wave
189
Trough
the bottom of a wave
190
Undisturbed position
Midpoint between the peak and the trough
191
Compression
area where longitudinal waves are close together
192
Wave Speed
wave speed = frequency x wavelength
the speed at which the energy is transferred, or the waves moves, through the medium, measured in metres per second, m/s
193
Ripple tank
a specialised form of wave tank used for demonstrating basic properties of waves
194
Incident Rays
the original rays
195
Reflected rays
rays that are reflected
196
Normal
the point at which incident rays are reflected and become reflected rays
197
Angle of incident
the angle at which an incident ray hits the normal
198
Angle of reflection
the angle at which a reflected ray leaves the normal
199
The Law of Reflection
the angle of incidence = the angle of reflection
200
Ray Diagrams
diagrams used to show rays and how they are reflected
201
Sound of Speed in Air
330m/s
202
Outer Ear
the external part of the ear that directs sound waves
203
Ear Canal
pathway from outer ear to eardrum
204
Cochlea
convert auditory signals to neural impulses
205
Ear Drum
thin membrane that is vibrated by sound waves
206
Auditory Nerve
nerves that allow you to hear
207
Hammer
small bone in the ear that vibrates to allow you to hear
208
Anvil
small bone in the ear that vibrates to allow you to hear
209
Stirrup
small bone in the ear that vibrates to allow you to hear
210
Pure Note
a note with constant frequency and amplitude
211
Impure Note
a note with inconsistent frequency and amplitude
212
Oscillation
repetitive vibrations
213
Oscillating
something that is vibrating
214
Visible Spectrum
consists of all the light we fan see: red, orange , yellow, green, blue, indigo, violet. Red is the longest wavelength and is refracted the least, whereas violet is the shortest wavelength is and is refracted the most
215
Infared
wavelength beyond red that we can't see, refracted less than red and its wavelength is longer
216
Ultraviolet
wavelength beyond purple that we can't see, it is refracted more than violet and its wavelength is shorter
217
Ionosphere
layer of the atmosphere that reflects radio waves
218
Aerial
a long wire that produces radio waves when an oscillating current is passed down it
219
Optical Fibres
fibres that light van be passed down, used in endoscopies and colonoscopies
220
Endscope
contains two bundles of fibres that transmit light into a body cavity for medical examination
221
Radar
radio wave
222
Sky TV
radio wave
223
SAT NAV
microwave
224
Bluetooth
radio wave
225
Light house
visible light
226
Mobile phone
microwave
227
Remote control
infa red
228
Distress singals
visible light
