2. Suggest two methods to find out wind direction at a given
3. State two experiences that made you think that air exerts pressure
(other than those given in the text).
4. You want to buy a house. Would you like to buy a house having windows
but no ventilators? Explain your answer.
5. Explain why holes are made in hanging banners and hoardings.
6. How will you help your neighbours in case cyclone approaches your
village/town?
7. What planning is required in advance to deal with the situation created
by a cyclone?
8. Which one of the following place is unlikely to be affected by a cyclone.
(i) Chennai
(ii) Mangaluru (Mangalore)
Answers
Answer:
The two methods to find out in which direction wind is blowing are as follows:-
1.If we fly a kite, the direction in which kite flies tells about the direction of the kite.
2.Tie a thin plastic sheet or cloth with a stick. Keep the stick at a place which is as high as possible. The direction in which the cloth sways shows the direction of wind.
Q.3 : I have seen paratroopers jumping from aeroplanes. The parachute helps them in reaching the ground safely. The air pressure reduces the speed of the parachute and the paratrooper lands without getting injured.
Q.4 A house should have ventilators along with windows. The warm air would rise up and exit from the ventilators. The cooler air would rush in through the windows. This will help in making the rooms comfortable. A room without ventilators shall not be cooled as efficiently as one with ventilators.
Answer:
The following are the two methods to find out the direction of wind.
(i) While flying a kite, air exerts pressure on the kite due to which the kite flies. The direction in which the kite flies is the direction of blowing of wind.
(ii) While riding a bicycle, the direction in which it is difficult to ride is opposite to the direction of the blowing wind.
Therefore, while flying a kite or riding a bicycle, the wind direction at a given place can be determined.