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Sunday, 30 October 2011

Activity Zone- Energy in A Day

    Energy in a day
   1. List all activities that you do in a day.

   2.  Write the time and place,these activities are carried out.

   3. Identify the activities that use energy.Explain why energy is
       needed in these activities.

  4. Compare your list   with you friend.
                                 


Energy story:

 Mei Ling is eleven years old. She uses different forms of energy every day.She gets up at 6a.m..She likes to have bread for breakfast.Her mother prepares toasts for her. At 7a.m., she waits for a van to go to school. The van uses petrol.Mei Ling likes to study science at school.She and her friends go to the science garden to study about plants. At night ,Mei Ling does her homework.She uses her favourite lamp on her study table. Before she goes to bed,she sometimes watches television.

 Can you identify where and when Mei Ling uses energy in the story given.

Saturday, 29 October 2011

Sources of Energy

Energy is everywhere in nature.Example are solar,wind, water, plants and animals.Energy from the sun can be converted directly or indirectly into other forms of energy,such as heat and electricity. Calculator, space vehicles and satellites use solar cells,which convert sunlight into electricity.

 The Sun gives us heat and light energy. Plants use sunlight to make food. Human and animals get energy from the food they eat.Their sources of food include plants and other animals.

The laundry uses the sun's heat to dry.

Fuels such as coal,petroleum and natural gas are sources of energy too. These fuels are formed from dead plants and animals that lived millions of years ago.






Dry cells can store energy for long time.



Wind can be used to work. A sail boat uses the wind energy to cruise.





 The difference in temperature and atmospheric pressure produce wind. Humans have been using wind energy for over 2000 years. The energy is used to sail ship,grind corns or pump water.Wind turbines are used to harness the movement of air to produce electricity. The wind turns the blades,which turn a rotor shaft. this produces mechanical power used to drive an electric generator. To produce large amounts of electricity, many machines are installed together to form a wind farm.


          windmill                                         wind farm



Why is food a source of energy?
  By eating  plantings, humans and animals take these energy storing molecules to maintain their life processes. By eating animals,the energy captured by plants is obtained. Thus,the food we eat contains energy. We use that energy to work and play.


 From all the different sources of energy,the Sun is the main source and such is the ultimate source of energy.


Tuesday, 11 October 2011

Wonder of Energy

Energy is to our lives. We use energy to do work. Energy lights up our cities. Energy moves our cars,trains and enables us to watch televisions.

Why Energy is Needed by Living and Non-living Thing? 
 
Living  things carry out life processes. Energy is needed to carry out these processes.


  • Living thing need energy to breathe.


  • Food produces energy for living things to  grow.                                                                                                                                                                                                                  

 


  • Living things need energy to move and do all kinds of work.