Thursday 8 December 2011

Uses of Magnet

Magnet are of many use in our everyday life.What are some uses of magnets?

Refrigerator
- A magnet operates the motor .
- The door closes with the help of a magnet.
Pencil case
- A magnet pulls the lid of the pencil case shut.
Chess
-There is a button magnet on the base of every chessman so that they are stuck to the chessboard
Music box
- A magnet makes the figurine rotate when the box is opened.
Compass
-The needle is made from a magnet
-The needle always points to the direction of the magnetic north.
Bicycle
-The dynamo is operated bay a magnet.
-When the wheel turns,the magnet in the dynamo also turns and this in turn lights up the bulb.

The Light Rail Transit uses magnet to operate.
We will not be able to get electricity without magnets.Without magnets there will be no telephone, radio or television.
 

        refrigerator              compass                            chess

Magnets Attract Some Materials

Materials that are attracted by magnets
- needle
- iron ruler
- key

 paper clip 

                                                                                                         

  drawing pin                                                    safety pin
                                                                                                                
Materials that cannot be attracted to magnets



coin

  • wood
  • plastic bottle 
  • paper
  • marble
  • pencil
  • book
  • handkerchief
Magnets attract things that are made of iron or steel.
Magnets do not attract things that are made of silver plastic or wood.


Magnets can Attract or Repel Each Other

Shape of magnets              
                                                                                     rod magnet
     
                                                       South pole                 North pole 

There are two types of magnets, natural magnets and man-made magnets.

Like poles of magnets repel each other
Unlike poles of magnets attract each other
when you break a bar magnet into two, you do not separate the North poles from the south poles. You will instead get two new magnets.

Magnets will lose their magnetism if:
1.dropped
2.heated
3.knocked
We should keep a magnet properly after use to avoid it losing its magnetism.

External Features of Plants

Surface, colours and shapes of leaves
1. sunflower leaf                  
   surface: smooth
   colour: green
   shape: heart-shaped






2. rose leaf
   surface: smooth
   colour: green
   shape: oval






3.bird's nest fern
   surface: smooth,shiny
   colour: green
   shape: long








4.coconut leaf
   surface: smooth
   colour: green
   shape: comb-like





5.papaya leaf
   surface: smooth
   colour: green
   shape: heart-palmate








Plant with woody stems and soft stems

    Flowering plants and non-flowering plants                                

  • Most plants have green leaves.
  • The shapes of leaves can be heart-shaped,oval,long,comb-like,palmate and round.
  • Flowers function mainly as reproductive organs.



Grouping of Animals

1. Animals can be grouped according to their similar external features.
i. animals with fur
   - bear  - lion                                                 
ii. animals with scales
   -crocodile  -fish
iii. animals with horns
    -cow  -goat 
iv. animals with feathers
     -duck -eagle
v. animals with tail
-deer,tiger
vi. animals with wings
     -bee  -eagle                                                                                              
 A bird has wings and some insects also have wings.

2. Animals can be grouped according to their similarities.                                      
i. animals with                                                                                             
    -beak  -feathers  -wings  -claws  -two legs
     parrot , eagle                                                                                                   
ii. animals with 
    -tail   - scales                                                                                                  
     crocodile , fish
iii. animals with
    -fur  -four legs -tail
     bear , deer
Some animals have fur and some animals have scales on their bodies.       

3. Animals can be grouped according to their number of legs.                                
i. two legs
  -duck, eagle
ii. four legs
   -lion,cow,tiger
iii. six legs
    -mosquito,bee
Birds have two legs. Insects have six legs.


   
 

Sunday 4 December 2011

Similarities and Differences External Features

  • Animals have similarities and differences in their external features.
  • we can recognise an animal from its external features.
  1. Animals which have similar external features.


               
 A mouse and  a cat have claws, fur, legs and tails.




     2.   Animals with different external features.


                                     
    A goat have hair                                A rhinoceros have skin



External Features of Animals

Each kind of animal has its own external features


                                                  External features of a crocodile
                                                  External features of a goat
                                     External features of a peacock