Thursday, January 22, 2015

Force



                 FORCE


Fill in the blanks
1. We can move object either by push or by pull.
2. This push or pull is called force.
3. We need more force to move a heavy object.
4.  Object  that  are light need less force to move a object.
5. We use force to change the direction of a moving object.
6. Force is used to stop the motion of a moving object .
7. We cannot see force, but we can see and feel its effect on things.
8. Air and water can make things move because they can exert force.
1.Name some everyday activities which require force.
 Ans. Bathing, wearing   clothes, walking, dancing etc.
2. Differentiate between a ‘push’ and a ‘pull’.
Ans .When we are applying force to move the object far from me then that force  is known as push .
When we are applying force to bring the object near me then that force is called pull.

3. Effects of force./ what happens when force is applied to an object.

1.   Force  can  increase the  speed of an object,
2.  Can change directions  of the object.
3.  Can slow down or  stop  the motion.
4.   It also changes the shape of an object.

4. Give  examples to explain---------
a). How force leads to change in direction?
  Ans. In cricket  match  when a bat hits a ball.

b). How force can stop an object  completely ?
Ans. When brakes are applied in a moving bicycle.
c).   How force can change the shape of an object.
Ans. When we make a  chapatti  we  can turn the small round    of  dough into a big chapatti by applying  force.
d). How ‘turning of things’ also  require force.

Ans.   When we  turn the water-bottle caps and sip some water.

5.  Why any object floating on water moves a little on its own?

  Ans. Object floating on water moves a little on its own because water possesses force.

6.  Explain water has force?

Ans. A boat floats on the water because water gives a vertical force to the boat.

7. How do kites fly in the air?
Ans. Kites fly in the  air  because air has force  .
8. How do you know that I applied force while writing?

 Ans.  We know that you have applied force because we  could see the effect.



Oceans and Continents





CH – 11 OCEANS AND THE CONTINENTS
Q-1.  FILL IN THE BLANKS:
   1. Large water bodies on earth are called oceans’
     2. The big pieces of land on earth are called ‘continents.
3. Pacific Ocean is the largest ocean in the world.
4. Australia is known as the “Island Continent”.
5. Asia is the largest continent in terms of population.
6. Mt. Everest in the Himalayas is the highest peak in the world.
7. Many countries together form a continent.
8. It has around 30% of the world’s land area and 60%
of the world’s population.
9. North America is 3rd largest continent in area
and 4th largest in population.
10. The Anaconda snake is found in the shallow
waters of Amazon basin.
11. Australia is the largest island and the smallest
 continent of the world.
12. Antartica is known  as frozen continent.





Q-2.  Name the following:-
1.     Longest river of Asia            -  Yangtze
2.     Largest desert of Asia          -  Gobi desert
3.     Dark continent                      -   Africa
4.     Largest desert of the world  -  Sahara
5.     Highest peak in Africa          -  Mt. Kilimanjaro
6.     Longest river of the world     -  Nile
7.     Longest mountain range        -  The Andes
8.     World’s driest hot desert        -  The Atacama Desert
9.     Second longest river in world – Amazon
10.                       Smallest continent of the world – Australia
11.                       Disneyland is in                           -   France
12.                       River Thames                    -   United Kingdom(U.K.)
13.                       Eiffel Tower                                    -   France
 
Q-3. QUESTION AND ANSWERS:
Q-1. How many oceans are there on the Earth? Name them.
Ans. There are 5 major oceans on the Earth. They are Pacific Ocean, Southern Ocean, Arctic Ocean, Atlantic Ocean and Indian Ocean.

Q-2. Name the major continents of the World.
Ans.The world is divided into 7 major continents. North America, South America, Africa, Asia, Europe, Antarctica and Australia.

Q-3. Name some Asian countries.
Ans. India, China, Iraq, Thailand, Sri Lanka, Saudi Arabia,  Pakistan, Russia, etc.

Q-4. Name some important rivers flowing in Asia.
Ans. Yangtze, Huang Ho, Euphrates, Tigris, Indus, Ganga, Brahmaputra, etc.

Q-5. Give specific details about different oceans.
Pacific ocean
Atlantic ocean
Indian ocean
Southern ocean
Arctic ocean
Largest and deepest ocean
Second largest ocean
Third largest ocean
Located around the south pole
Smallest and shallowest ocean
Covers more than 30% of the earth’s water surface
Half the size of Pacific ocean
Covers 20% of the earth’s water surface
The habitat(home) of penguins
Permanently covered with ice
There are 20,000 islands in this ocean
Covers 21% of the earth’s water surface




Q-6. What is the location of Europe?
Ans.  Europe lies north of the African continent, south of the Arctic Ocean, west of the Asian continent and east of the North Atlantic Ocean. It is separated from Asia by the Ural Mountains and Caspian Sea.

Q-7. Name the 5 largest countries in the world.
Ans.  Russia, Canada, China, USA, Brazil

Q-8. Name the 5 smallest countries in the world.

Ans.  Vatican , Monaco, Nauru , Tuvalu, San Marino.

Q-9.Why do you think does the reef attract 1.6 billion tourists every year?
Ans.  The Great Barrier Reef is the largest coral reef in the world and a home to many marine species. Divers from all over the world travel to see the giant reef, for its unique & striking beauty, their diversity of marine life, its size.

Q-10. Which are the rivers that flow in South America?
Ans. Amazon, the second longest river in the world, the Parana – Paraguay and the Orinoco.

Q-11. Name the mountain ranges in Asia.
Ans. Asia is a home to many high mountains ranges such as the Himalayas, Karakoram, Hindu Kush, Knlun, Ural, Tien Shan and Altai.



Oceans
Sea
1.   Oceans are vast bodies of water that cover roughly 70% of the earth.
1.   Sea is a body of salt water that is surrounded by land on all or most sides, or that is part of one of the oceans.
2.   Oceans are deeper and larger than seas.

2.   Seas being close to land are generally much shallower than oceans.

Q-4. Give reasons:

1.     Africa is known as the ‘Dark Continent’.
Ans.   For long time it was not much known about Africa , due to its difficult environment. Therefore it is also known as ‘Dark Continent’.

2.     Australia is known as ‘Island Continent’.
Ans.   Australia is the largest island and the smallest continent of the world and therefore it is known as the ‘Island continent’.

3.     Antarctica is also called as ‘Frozen Continent’.
Ans.   Antarctica is a frozen land area around the South Pole. Its lowest temperature recorded is -89.2o c. (-129oF). The ice is said to be 4 km. thick. Therefore it is known as ‘Frozen Continent’.