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What is magnetism?
Force of attraction and
repulsion
What causes magnetism?
The spin of electrons
Where is the strongest point in
a magnet?
The poles
What happens to the magnetism of a
wire carrying electricity if you add
more coils?
It becomes stronger
What is the magnetic field?
The space around a magnet
How can we create a
magnet?
• Rub a piece of iron with a magnet in one
direction
• Attach a piece of iron to a magnet
• Use electricity
What is the magnetosphere?
Field around the earth
How does the earth’s
magnetic field help us?
Protects us from the sun
Draw the north pole next to the
south pole of two magnets?
they attract one another
Where is the electric field of a
charged object the strongest?
On the outside (surface)
of an object
What charge does an object have
if it doesn’t have enough electrons
on it?
•positive
How do you make an
electric field stronger?
Take away negative
or
Add positive
Draw the electric field around two
positive objects?
They repel
What happens when two objects that
have opposite charges come near
each other?
They attract each other
What is the rule of charges?
Opposites attract,
Same repel
What charge does an object
have if it has too many
electrons on it?
Negative
What is the electric field?
Area around a charged
object
Draw the electric field around a
negative object?
What happens when two objects
that have the same charge come
near each other?
They repel each other
How much current can be pushed
through a 5 ohm resistor if the
voltage is 10 volts?
V=IxR
10 = I x 5
10/5 = 2 amps
What is the symbol for current?
What is a wet cell?
A battery that has
liquid inside
What are the electrons doing
an AC wire?
The electrons are going
back and forth
What is the voltage in your
house wiring?
120
What is current?
A flow of electrons
What is a voltage?
Push of electrons
What is resistance?
Friction to electrons moving
What are 3 ways to transfer
heat?
Convection
Conduction
Radiation
Give an example of heat
transfer by radiation?
putting your hand by your
forehead
Give an example of heat
transfer by conduction?
Pan on a burner of stove
Give an example of heat
transfer by convection?
Hand over a radiator
What are insulators?
Something that slows down
heat transfer
What is heat?
Energy of molecules in motion
What happens to the molecules of
a liquid as heat is added to it?
Molecules speed up
What are conductors?
Substances that allow electrons
or heat to go through them
(tend to be metal)
What happens to the molecules of a
hot object if it touches a cold object?
They slow down
Why can’t we say that heat
rises?
Objects rise – not
energy
What units is heat
measured in?
Joules and Calories
What is temperature in terms
of molecules?
How fast molecules are
moving
What do we use to measure
temperature?
thermometer
What is the Celsius
thermometer based on?
Freezing = 0 degrees
Boiling = 100 degrees
What is the Kelvin
thermometer based on?
The speed of molecules
Why can’t there be a temperature
below zero degrees Kelvin?
Because molecules stop at
zero
Why do bridges have expansion
joints?
To protect from cracking in hot
weather and pulling apart in cold
weather
Why is it that most materials expand
when heated?
Molecules move faster and
further away from each
other
Why does water expand when cooled
to zero degrees Celsius?
Water freezes and traps
space between molecules