Friday, 30 November 2012

How do magnets work ?

How do magnets work ?
A magnet is a very special metal. When a magnet goes near a special kind of metal or other magnets, and the poles (sides) touching are opposite, it will pull, or attract the other metal or magnet closer. Also, if the two poles are the same, the two magnets will push away, or repel, from each other. This is called magnetism. Like poles (S-pole and S-pole/N-pole and N-pole) will repel each other while unlike poles (N-pole and S-pole) will attract each other.

Magnets are only attracted to special metals. Metals that have iron and steel attract magnets well. Metals like brass, copper, zinc and aluminum are not attracted to magnets. Also, non-magnetic materials such as wood and glass are not attracted to magnets as they do not have the right particles inside them like magnetic materials do.

A compass uses the Earth's magnetic field, and will always point to the North Pole. A north side of the magnet is attracted to the south side of another magnet. However, the north side of the compass points to the north pole, this can only mean that the "north pole" is really the magnetic south, and the "south pole" is really the magnetic north.

Thursday, 29 November 2012

Tuesday, 27 November 2012

External features of plants

Flowering or non-flowering plants

How to group animals according to thier foods ?

There are thousands of animal species in the world. Scientists classify animals into groups to help us understand the animal kingdom better. Animals can be classified in a variety of different ways.

What is a herbivore?
It is possible to group animals together based upon what they eat. Herbivores are animals that only eat plant material. Herbivores gain the nutrients they need from plants and leaves which store energy received from the sun. Herbivores need wide, hard-wearing teeth to munch on chewy plants. Some examples of herbivores include cows, sheep, horses and snails.

What is a carnivore?
A carnivore is an animal that mostly feeds on meat. Some carnivores, such as lions, stalk and kill their own prey, while other carnivores, such as hyenas, search for already dead carcasses to feast on. Carnivores need very sharp teeth and strong jaws for tearing meat from the bone. Lions, tigers, crocodiles, polar bears and wolves are all examples of carnivores.

What is an omnivore?
Omnivores are animals that eat both meat and plants. As you might expect, an omnivore has a reasonable amount of variety in its diet. A grizzly bear is an omnivore that eats fish and meat as well as grasses, nuts and berries.  

Thursday, 15 November 2012