Friday, January 25, 2013

PLANET EARTH TEST

Here you have a test to practice:

WORLD MAPS


Maps are flat drawings that represent parts of the surface of the Earth.
On a world map, you can see:
• The six continents: America, Europe, Asia, Africa, Oceania and Antarctica.
• The five oceans: the Atlantic, the Pacific, the Indian, the Arctic and the Antarctic Ocean.



EARTH GLOBES



Earth globes are spheres which represent the planet on a small scale.
They show:
• The North Pole.
• The South Pole.
• The Equator: an imaginary line dividing the Earth into two halves: the Northern Hemisphere and the Southern Hemisphere.

 
 

Thursday, January 24, 2013

ARTIFICIAL SATELLITES


Artificial satellites are man-made objects which orbit the Earth.
They have many different functions.
They send information back to Earth about the weather and the land.
They are also used for telecommunications.
We use this information to create maps and globes to represent Earth.

Photo from Bharat Defence Kabach

Tuesday, January 22, 2013

THE CARDINAL POINTS


The cardinal points are the four main points of a compass: North, South, East and West.

Photo from The Solid Signal Blog

THE MOON MOVES


The Moon orbits the Earth. Each orbit takes 28 days.
This is called a lunar month.
There are four shapes called the Moon phases.

Photo from www.relativelyinteresting.com

THE EARTH ORBITS THE SUN


The Earth orbits the Sun.
One complete orbit takes 365 days.
This is called an Earth revolution or a year.
 Earth revolution causes the four seasons.
The Earth rotates on a tilted axis.
In winter, the Sun’s rays reach the Earth at an angle.
This gives less heat.
In summer, the rays reach the Earth more directly. This gives more heat.

Photo from learner.org

Photo from nmsu.edu

Photo from nmsu.edu

THE EARTH ROTATES


The Sun does not move.
The Earth moves around the Sun.
The Earth rotates on its axis.
This movement is called rotation.
One rotation takes 24 hours.
This is a day.
The rotation of the Earth causes day and night.
It is day in the half that receives the light from the Sun.
It is night in the half that does not receive light.

Monday, January 21, 2013

THE MOON


The Moon is the natural satellite of the Earth.
Satellites orbit planets.
The Moon is a sphere.
The Moon does not give off light.
It looks bright because it reflects light from the Sun.

THE SUN


The Sun is a star.
Stars are like giant balls of fire.
The Sun is like other stars you see in the night sky.
You can see the Sun during the day because it is closer to the Earth than other stars.
Life on Earth is possible thanks to the light and heat from the Sun.
Photo from the NASA

THE EARTH


The surface of the Earth is covered with land and water.
The land is made up of continents and islands.
Continents are large areas of land.
Islands are land surrounded by sea.
Most of the Earth is covered with water.
This water forms the seas and oceans.
There is also water on the continents and islands, in rivers and in lakes.
The Earth is surrounded by a layer of air called the atmosphere.

Sunday, January 20, 2013

THE MOON AND THE SUN


The Moon orbits the Earth.
There is no water or air on the Moon.
The Sun is a star.
It is the closest star to the Earth.
Picture by Larry McNish

THE EARTH


The Earth is a planet.
It is shaped like a sphere.
The Earth rotates.
It spins on its axis.
The Earth orbits the Sun.
There is water and land on the surface of the Earth.
The Earth is surrounded by a layer of air called the atmosphere.

Photo from www.factmonster.com

Tuesday, January 15, 2013

MACHINES TEST


COMPOUND MACHINES



Compound machines are made up of two or more simple machines working together.
They are classified into groups:
Motors produce movement. They can be electric or gas.
Gears are wheels with teeth that produce movement.
Electric circuits have switches and wires. They help electricity flow through the different parts of a machine
Electronic circuits are electric circuits with very small parts called microchips.

Motor by Miguel Díaz from flickr
Gears by ralphbijker from flickr
Electric circuit by Leslie Wong
Microchip from pixabay

Monday, January 14, 2013

SIMPLE MACHINES



Simple machines have one or few parts.
They work with one movement.
The wheel is a solid disk that turns on an axle.
The pulley is a rope wrapped around a wheel.
The lever is a bar that rests on a pivot point.
When one side goes down, the other side goes up.
The ramp is an inclined plane.

Friday, January 11, 2013

HOW MACHINES FUNCTION


Machines need energy in order to function.
This energy comes from different sources:

  • People are the energy source for canoes and bicycles. 
  • Electricity is the energy source for refrigerators and computers. 
  • Combustible fuels are the energy source for cars and rockets. 
  • Wind is the energy source for windmills and sailing boats.

USES OF MACHINES


Machines have many uses:

  • Exerting force.
  • Carrying heavy objects.
  • Communicating with people far away.
  • Travelling.

WHAT IS A MACHINE?


Machines are devices that allow you to work better, faster and easier.
They help you save time and energy.
Machines can be very simple (scissors) and also very complicated (aeroplanes).

Tuesday, January 8, 2013

MACHINES


Machines make work easier.
They are very useful.
We use them every day for many things.
Machines can have one or few parts, for example the hammer, or they can have many parts, for example the car.
Car: many parts.
Photo by Leslie Wong
Hammer: few parts.
Photo by Anna Strumillo