Class 7 - Physics - Winds, Storms and Cyclones

Question1.

Fill the missing word in the blank spaces in the following statements:

(a) Wind is________ air.

(b) Winds are generated due to_______ heating on the earth.

(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.

(d) Air moves from a region of _______ pressure to a region of_____ pressure.

(a) Wind is moving air.

(b) Winds are generated due to uneven heating on the earth.

(c) Near the earth’s surface warm air rises up whereas cooler air comes down.

(d) Air moves from a region of high pressure to a region of low pressure.

Question2.

Suggest two methods to find out wind direction at a given place.

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.  When we put our clothes to dry, the direction in which clothes will be carried away tells about the direction of the wind.

Question 3.

State two experiences that made you think that air exerts pressure

(other than those given in the text).

Two experiences which make us think that air exerts pressure are as follows:-

1. When we inflate a balloon, after sometime even if we blow air the balloon won’t inflate any more. It might burst but will not inflate because air exerts pressure.
2. When we open the window panes the curtains tend to move, this movement is due to the pressure exerted by the wind.

Question 4.

No. I would not like to buy a house which has windows but no ventilators because windows are located at the lower height

but the ventilators are at the higher height. Ventilators help the room to be cool because warm air

will start rising and as ventilators are present so the warm air will come out through the ventilators.

Question 5.

Explain why holes are made in hanging banners and hoardings.

Holes are made in hanging banners and hoardings as holes reduce the air pressure exerted

on the banners and hoardings.

The air gets some spaces to pass through the holes. Holes prevent the banners or

hoardings from being blown away with the wind.

Question 6.

Steps taken to help our neighbours in case of cyclones approaches our village/town are as follows:-

1. Once the warning is issued we should shift to cyclone shelter as they are cyclone resistant buildings.
2. Try to provide clean drinking water as during cyclones water gets contaminated with undesirable substances.
3. Medical facilities to the injured.

Question 7.

What planning is required in advance to deal with the situation created by a cyclone?

The planning required in advance to deal with the situation created by a cyclone are as follows:-

1. Cyclone shelters can be built.
2. Drinking water can be stored.
3. Medicines and food materials can be stored for future use.
4. People can prepare to shift during emergency.

Question 8.

Which one of the following place is unlikely to be affected by a cyclone -

(i) Chennai (ii) Mangaluru (Mangalore) (iii) Amritsar (iv) Puri.