Post on 21-Jul-2015
Biomass
Solar
Geothermal
Water
Wind
We do not exhaust
them because
they renew
themselves
continually.
Nuclear
Oil
Natural Gas
Coal.
We are exhausting
them because we
consume them more
quickly then they
form.
Renewable and Nonrenewable
sources.
Non renewable
Renewable
Click here if you want to know more in Spanish.
http://www.wikisaber.es/Contenidos/LObjec
ts/what_is_energy/index.html
1.What is light?
Some objects emit a form of energy
called light. These objects are called
light sources.
The sun,
the flame of a candle
a light bulblight sources
2.- How does light travel?
Light travels in straight lines:
Laser
Each of the straight lines is
called a ray of light.
Light travels much faster than sound.
For example:
1) Thunder and lightning
start at the same time,
but we will see the
lightning first.
2) When a starting pistol is
fired we see the smoke
first and then hear the
bang.
Light travels VERY FAST – around 300,000 kilometres per second.
At this speed it
can go around
the world 8
times in one
second.
Luminous and non-luminous objects
Objects that produce light are LUMINOUS
Objects that do not emit light are NON LUMINOUS
Luminous
objectsReflectors
3.- Effects on materials
If the material lets light pass through. It is transparent.
Example:
Glass, water, air,plastic.
3.- Effects on materials
If it lets some
light pass
through
It is translucent.
Some types of
glass and plastic.
3.- Effects on materials
If it does not let light pass through. It is opaque.
Examples:
Wood, iron, rock.
4.- Properties of light
* Reflection let us see objects
that do not emit light.
When light reaches and opaque
object, it hits the object and light
changes it direction.
It reflects light.
4.Properties of light
* Refraction: when a ray of light
goes from air to water it changes its
path.
The light rays are
slowed down by the
water.
Seeing colour
The colour an object appears depends on the colours
of light it reflects.
For example, a red book only reflects red light:
White
light
Only red light
is reflected
A white hat would reflect all seven colours:
A pair of purple trousers would reflect purple light (and red
and blue, as purple is made up of red and blue):
Purple light
White
light
Using coloured light
If we look at a coloured object in
coloured light we see something
different. For example, consider a
football kit:
White
light
Shorts look blue
Shirt looks red
In different colours of light this kit would look different:
Red
light
Shirt looks red
Shorts look black
Blue
light
Shirt looks black
Shorts look blue
Click here if you want to know more in Spanish.
http://www.wikisaber.es/Contenidos/LObjec
ts/refraction/index.html
1.-What is Magnetism?
Magnetism is the power of magnets to attract things.
A magnet is an object that can attract metal objects made of iron, steel, nickel and some other materials.
2.-What is a magnet?
Magnets have been known for centuries.The Chinese and Greeks knew about the “magical” properties of magnets. The ancient Greeks used a stone called “magnetite.” They discovered that the stone always pointed in the same direction.
3.- TYPES OF MAGNETS
NATURAL MAGNETS
ARTIFICIAL MAGNETS
Are found in nature. For example some rocks
Are man-made. They are usually made of iron or steel.
lodestone
Object Material Predictio
nResult Was your answer
correct?
PENCIL
PAPER CLIP
COIN
MARBLE
SCISSORS
KEYS
PEN
What will make a magnet move?
XWOOD YES
Object Material Predictio
nResult Was your answer
correct?
PENCIL WOOD
PAPER CLIP IRON
COIN Steel
covered
by Copper.
MARBLE GLASS
SCISSORS IRON
KEYS IRON
PEN PLASTIC
What will make a magnet move?
X
X
4.- The poles of a magnet.
The poles are the parts of the magnet that Exert the strongest force on metal objects.
The blue end of a magnet is usually
the south pole.
The red end of a magnet is usually the
north pole.
1.-Tie the thread around the middle of
one of the magnets.
2.- Hold it up by the thread.
3.- Use the compass to see which is
the north end of the magnet. (The
north end of the magnet will point in
the same direction as the north
pointer in the compass).
4.- Repeat for the other magnet.
Then answer the questions.
If you put two magnets together with
different poles pointing towards one
another, the magnets will pull towards
each other. We say they attract each
other.
In this picture a north and a south pole are
pulling towards each other (attracting
each other).
If you try to put two magnets together with
the same poles pointing towards one
another, the magnets will push away from
each other. We say they repel each other.
Magnets are in most electronic devices, in fact,
anything that has a motor uses a magnet.
They are used to slow down roller coasters and subways.
More uses of magnets are found every day!
A magnet has a
‘magnetic field’
distributed throughout
the surrounding space
Michael Faraday realized that ...
William Gilbert, an English
physician, first proposed in
1600 that the earth itself is a
magnet, and he predicted
that the Earth would be
found to have magnetic
poles.
The Earth is a magnet:Magnetic South Pole
Magnetic North Pole
It exerts magnetic
forces and is
surrounded by a
magnetic field that is
strongest near the
North and South
magnetic poles
Geographic North Pole
Geographic South Pole
We use the Earth’s magnetic field to find direction.
The needle of a compass always points toward the magnetic
south pole.
We call this direction “North” (remember, opposites attract)
The sun sends out a
solar wind made up of
light particles which
blow toward the earth.
As the solar wind hits the
Earth's magnetic field, some if it
is sent into the Earth's
atmosphere
when the light particles spill into this
"ocean" the particles collide with gases in
the atmosphere causing the particles to
glow, which produces the lights they see in
shades of red, green, blue and violet.
The Aurora Borealis in the
Northern Hemisphere
Aurora" means "down
"Borealis" means "north wind."
And the Aurora Australis in the Southern
Hemisphere