Phy4.1-5.9 Flashcards
(108 cards)
1
Q
charge
A
physical property of a matter that causes it to experience a force when placed in an electric field
Can be both positive or negative
Is a property of protons and electrons
2
Q
Electrostatic phenomena
A
things that happen because objects have become charged
3
Q
2 types of electric charge
A
positive charge and negative charge
4
Q
When you bring charges together, — occurs.
A
electrostatic attraction or repulsion
5
Q
electrostatic force
A
the force between 2 charged objects
6
Q
When you charge a balloon by rubbing it, it can
— in scraps of paper, running water, or a wall. This leaves —, which –.
A
repel the negative charge; a positive charge; produces attraction
7
Q
In a simple model of an atom, - and - make up the —. The electrons —.
A
protons; neutrons; central nucleus; orbit the nucleus
8
Q
In an atom the number of electrons, which are –, is always – as the number of protons, which are –, so an atom has –. We say that it is - ( no – ).
A
negatively charged; the same; positively charged; no charge overall; neutral; net charge
9
Q
if you move —, the materials become -.
A
electrons out of one material into another; charged
10
Q
When you rub a polythene rod with a cloth, electrons are transferred —. The rod now has —.
When you rub a Perspex rod electrons are transferred —.
A
from the cloth to the rod; a net negative charge because there is not enough
positive charge to neutralise the negative charge
from the rod to the cloth
11
Q
Charge cannot be —, just like energy or mass.
A
created or destroyed
12
Q
Electric field
A
a region around any charge where another charge experiences a force
13
Q
static
A
electric charges that are not moving / stationary
14
Q
In an -, the electrons stay on the rod once you have rubbed it.
In a - (such as a metal) electrons can —. Any extra electrons will move —, and then through you to the earth.
A
insulator; conductor; move in it; through the metal to your hand
15
Q
If electrons move from one object to another, each object —.
A
will become charged
16
Q
In a conductor the electrons are —, but in an insulator —.
A
free to move; they are not
17
Q
Televisions, movie projectors, and loudspeakers all contain – that use
–.
A
electric circuits; electrical components
18
Q
8 circuit symbols
A
wire, cell, battery of cells, lamp, open switch, close switch, buzzer, motor
19
Q
circuit symbols
A
drawings that represents a component in a circuit
20
Q
In physics a battery —-.
A
contains two or more cells.
21
Q
You can join – in a circuit diagram to show —-.
A
circuit symbols; how the components in your circuit are connected
22
Q
terminal
A
Positive or negative end of a cell or battery
23
Q
A cell has a —-. When you connect cells together in a battery, you must make sure that —- or it will not work.
A
positive and a negative terminal; you do not connect two positive terminals (or two negative terminals) together
24
Q
On the circuit symbol the – represents the positive terminal, and the – represents the negative terminal.
A
long line; short line
25
1 non-metal conductor
graphite, a form of carbon
26
Why are wires covered in plastic?
Because touching bare wires is very dangerous, could make one get an electric shock
27
Electric current:
flow of charge
28
In a circuit made of metal wires, the flowing charge is caused by---. Electrons are --.
the movement of electrons; charged particles
29
Inside a copper wire there are --. Some of the electrons on the -- are --- and can leave the atoms and move around.
copper ions; outside of the copper atoms; not strongly bound to the atom
30
A battery provides ---. The moving electrons make ---. The current is -----.
a push to make the electrons move; an electric current; the amount of charge (electrons) flowing per second
31
Current is measured in ---,- for short. Small currents are
measured in ----. 1 mA = -- A, or -- of an amp.
You measure current with a meter called an -.
amperes (A); amps; milliamps (mA); 0.001; one-thousandth; ammeter
32
You change the current in a series circuit by 1, 2, 3.
Changing the number of components, the type of components, the number of cells
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Each component (ex. lamp) provides a ---.
resistance to the flow of charge
34
A series circuit has --.
only one loop
35
In a series circuit the current - if you add more lamps.
decreases
36
Models help us to work out ---.
Models can be used to -- if you change something in a circuit.
All models have-.
what is happening in a circuit; predict what might happen; limitations
37
Lightning is an example of ---.
an electrostatic phenomenon
38
If --- due to -, then a spark will form.
enough charge builds up; friction
39
A spark is ----, heating it up. (a flash of light when the air conducts electricity) The -- is an electric current.
charge moving through the air; moving charge
40
What happens during a thunderstorm?
* Inside the cloud the air moves around, like rubbing a rod with a cloth.
* The movement forms a region that is positively charged and a region that is negatively charged.
* Negative charges at the bottom of the thundercloud can make a huge spark as they
travel to Earth.
* We see that spark as lightning.
* Sometimes a spark is produced when charge moves between positive and negative regions inside the cloud.
41
It takes --- to make the air conduct electricity so that ---.
a big difference in charge; a current flows
42
Doctors in hospitals can use an electric current to --- using---.
try to restart a patient's heart if it stops beating; a defibrillator
43
Sometimes people feel a small shock when they touch a car door. This is because ---.
the car has become charged by friction as it has been moving along
44
Risk is a combination of --- and ---.
the probability of something happening; the consequence if it did
45
We can change what happens if lightning hits a building. If you want to reduce the risk of damage by an electric current, you can ---. This means---.
earth the object; connecting it to the ground with a conductor
46
Using the lightning conductor to do -.
Earthing
1. is a thick strip of metal, such as copper, running from the top of the building down the wall to a copper plate buried underground.
2. If lightning strikes the building, electrons flow down the strip and into the ground. (The metal conducts electricity much better than the building).
47
Because the - caused by moving fuel might cause --, and cause sparks, before making the fuel catch fire, fuel pipes are---.
Any charge that builds up will ---. This reduces the risk of a spark and an explosion.
friction; charge to build up; earthed by attaching a metal wire to it; flow down the wire to earth
48
Engineers wear ---. The build-up charge will ---, rather than through and - the delicate components.
special wristbands connected to a metal wire to the ground; flow down the wire to the earth; damage
49
* Lightning conductors -- of damage to buildings.
reduce the risk
50
* Earthing reduces the risk of ---.
sparks and shocks
51
Sun rises, move across the sky to --, then onwards till it sets.
its highest point at noon
52
At any one time, the light from the Sun ---. The other
---.
The Earth spins -- (angle of tilt: 23.5). Day and night are ---.
lights up half of the Earth; half of the Earth is in shadow; on its axis; caused by the Earth spinning every 24 hours
53
Looking down from the -- of the Earth, the Earth is --. This means that the Earth ---.
North Pole; spinning anticlockwise; rotates from the west towards the east
54
The Sun appears to move across the sky bc --.
the Earth's spinning
55
The Earth orbits the Sun once ---.We divide the year into ----. In some countries --- there is a --- between summer and winter. Other countries -- do not notice much change.
every year/ 365 days; seasons: spring, summer, autumn, and winter; near the poles; big difference in the weather; near the equator
56
The Earth's axis is tilted by ---. As the Earth orbits the Sun, for six months the ---, and for six months --- from the Sun.
North Pole is tilted towards the Sun; it is tilted away
57
The Earth's tilted axis explains (3)
Different day lengths in summer and winter
different temperatures in summer in winter
the varying height of the Sun in the sky in summer and winter
58
In the northern hemisphere in summer (3)
* the North Pole is tilted towards the Sun
* the Sun stays in the sky for longer each day as the Earth spins
* the day is longer than the night
59
In winter, the Sun stays in the sky for less time each day until -.
midwinter
60
The --- means that in summer inside the - and - ----. And in the winter of these places ----. These regions and the phenomenon are known as -and -.
tilt of the axis; Arctic circle; Antarctica; the Sun does not set; the Sun does not rise;
Land of the Midnight Sun; polar night
61
It is hotter in the summer than in the winter because
* the Sun is in the sky for longer
* the rays from the Sun are concentrated over a smaller area
62
If the rays hit the surface at 90 degrees then ----. This means (2)
more energy hits the surface per square meter per second
* the surface heats up faster
* the air temperature increases more quickly
63
The Earth's orbit is ---. It is slightly closer to the Sun in - each year.
nearly circular; January
64
Stars
Their light seems to flicker bc---
The only objects in the sky that ---
a body (huge ball of gas) in space that gives out its own light
When light travels through the Earth's atmosphere it changes direction
continuously give out light
65
Planets
Made up of-- and do not--- (---)
Large bodies that orbit a star in the solar system
rock and gas; give out their own light; (they are visible bc light is reflected off them into your eyes)
66
8 Planets; 2 dwarf planets in our solar system
Mercury, Venus, Earth, Mars, ( In the asteroid belt: dwarf planet) Jupiter, Saturn, Uranus, Neptune (Pluto)
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exoplanets
planets that orbit around a star other than our Sun
68
Moon aka --
(-'s moon is ---)
natural satellite; an object that orbits a planet; Saturn's moon, Titan is bigger than Mercury
69
Comets aka
(3)
hairy star; bodies in space made of dust particles frozen in ice orbiting the Sun
reflect sunlight; produce a tail when it gets nearer to the Sun; some come back again and again
70
Difference between planets and moons
Planets orbit the Sun, moons orbit the planets
71
Meteors (Meteor shower:--)
a piece of rock/ dust that makes a streak of light in the night sky; when Earth moves through the dust left by a comet
enters the Earth's atmosphere and burns up
72
Meteorite
a stony/ metallic object that has fallen to Earth from outer space without burning up
73
artificial satellites (ex.---)
part of GPS/ global positioning system (biggest and largest: International Space Station)
74
GPS
A system that pinpoints positions of things on Earth using signals from lots of satellites.
75
Stars--, but we can see other objects bc --.
emit light; they reflect light from the Sun
76
Our Solar System contains four--, an --, and four --. Planets are objects that ---. There are also dwarf planets ---. The outer planets have ---.
inner planets; asteroid belt; outer planets; have cleared their orbits of dust, gas, and rock; in the asteroid belt and beyond the outer planets; rings made of rock, dust, and ice
77
Inner planets are made of--
mostly rock
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Outer planets are made of--
mostly gas (helium, hydrogen) and/or ice
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Until 2006 Pluto was ---. Then astronomers found ---, so they started calling Pluto a --.
called a planet; other objects like Pluto beyond Neptune; dwarf planet
80
How the Solar System formed (3)
1. From a swirling cloud of dust and gas.
2. Gravity pulled the dust and gas together to make the Sun and all the planets
3. Some of the material formed rings around the outer planets
81
Gravity is a force that ---. There is a force --- all the planets and the Sun. It is this force that keeps the planets, comets and asteroids---.
acts between all objects with mass; of gravity between; orbiting the Sun
82
The Moon orbits the Earth every -- days.
27.3
83
Phases of the Moon=---
parts of the Moon that we see as it orbits the Earth
84
The light from the Sun --- the Moon, just as it lights up half of every planet and moon in the Solar System. The Moon appears to -- when seen from the Earth because ---.
lights up half of; change shape; it is moving around the Earth
85
The 8 different phases:
New moon; waxing crescent; first quarter moon; waxing gibbous moon; full moon; waning gibbous moon; third quarter moon; waning crescent
86
2 eclipses & their definition
solar: occurs when the Moon blocks out the light from the Sun
lunar: occurs when the Earth comes between the Sun and the Moon so that the Moon
is in the shadow of the Earth
87
The region of deep shadow, or -, is where you see a --.
Outside that region, in the -, you see a --.
umbra; total eclipse
penumbra; partial eclipse
88
Moon's slighted tilted orbit causes (2)
us to be able to see the full moon; eclipses to be rare (the Earth, Sun and Moon need to be lined up for a eclipse to happen)
89
Phases of the Moon happen bc (2)
half of the Moon is lit; it moves around the Earth
90
Tides are caused by
gravitation attraction of the Moon and Sun
91
Bulges of tides (2)
* There is a bulge of water either side of the Earth due to the force of gravity from the Moon.
* The Earth spins through the bulges, producing two high tides a day.
92
2 kinds of tides
* When the Sun and Moon are aligned there is extra force on the water, and we get a higher tide, called a spring tide.
* When they are not aligned ( Moon is at right angles to the Sun and the Earth ) we get a lower tide, called a neap tide.
93
Eclipses happen---
when the Earth or the Moon blocks out the light from the Sun.
94
Scientists' investigations for phenomenons (4)
1. Ask questions
2. collect evidence (making observations/ measurements)
3. develop explanations
4. some explanations use a model
95
2 models of the Universe
Geocentric model and heliocentric model
96
What is the geocentric model? (4)
The model where the Earth is at the centre of the Universe
1. The Earth did not move, but the stars and planets orbit around the Earth.
2. 7 spherical planets: Mercury, Venus, Mars, Jupiter, Saturn, Sun, Moon (stars beyond)
3. Move at a steady speed on transparent crystalline spheres
4. Moon is on the sphere closest to Earth, and the stars are furthest from the Earth.
97
The observation that the geocentric model did not explain:---
Retrograde motion: the apparent 'backwards' motion of planets due to the motion of the Earth and the planets around the Sun
* wander across the sky
* do not always go the same direction
98
Ptolemy changed the - model to explain the --- of the planets by ----
geocentric; retrograde motion; adding little circles on top of the bigger circles that were the paths of the planets
99
Evidence for the geocentric model (4)
-ground that you are standing on is not moving
-objects fall towards the centre of the Earth
-half of the stars were above the horizon and half below
-(if the Earth was moving then the stars would appear to move too) without telescopes, the stars did not appear to move
100
The geocentric model was easy to believe bc -------. Only when ppl had --- would the --change.
the Earth does not appear to be moving, but the Moon, Sun, and stars do; evidence from things that they couldn't immediately see; scientific explanation
101
Nicholas Copernicus was famous for ---. (3)
developing the heliocentric model;
1. the Sun is at the centre of the Universe
2. the planets are in orbits around the Sun
3. the Moon is in orbit around the Earth
102
Helio=. Geo=.
Sun; Earth in Greek
103
The heliocentric model was able to --- than the geocentric model.
Scientists look for--- of their observations. If explanations begin ---, then they will look for a --.
explain the motion of the planets much more simply; the simplest explanation; to get very complicated; simpler one
104
Galileo - his own -.
Evidence against the geocentric model
made; telescope
* Jupiter's moons do not orbit the Earth (planets orbit the Sun just like moons orbit Jupiter)
* Sunspots show that astronomical objects like the Sun are not perfect
105
Scientists might not know that an explanation has already been developed by someone else bc (3)
* not have been published
* had not reached them yet
* written in another language
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data
measurements or observations taken in an experiment or investigation
107
primary sources of data (ex.)
collected directly by scientists (ex. fieldwork, experiments)
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secondary sources of data (ex.)
collected by other scientists and published (ex. books, internet)
