F. Long Answer Type Questions
1. Describe an activity to demonstrate that air exerts pressure.
2. Suggest an activity to demonstrate that moving air lowers the pressure of the area it occupies,
3. How are cyclones caused?
4. What safety measures should be taken to prevent cyclone disaster?
5. How are winds caused?
Answers
Answer:
1.If the volume of the gas is kept constant , its pressure increases with the increase in temperature. For example, when the air is suck out of a bottle, the air present out side it exerts pressure in all possible directions of bottle . Due to this reason the bottle gets crushed
2.This activity again confirms that air exerts pressure. Crumple a small piece of paper into a ball of size smaller than the mouth of an empty bottle. Hold the empty bottle on its side and place the paper ball just inside its mouth. Now try to blow on the ball to force it into the bottle.
3.To form a cyclone, warm, moist air over the ocean rises upward from near the surface. As this air moves up and away from the ocean surface, it leaves is less air near the surface. So basically as the warm air rises, it causes an area of lower air pressure below.
4.During a cyclone
- Turn off all electricity, gas and water; unplug all appliances.
- Keep your emergency kit close at hand.
- Bring your family into the strongest part of the house.
- Keep listening to the radio for cyclone updates.
- If the building begins to break up, shelter under a strong table, bench or heavy mattress
5.Wind is air in motion. It is produced by the uneven heating of the earth's surface by the sun. Since the earth's surface is made of various land and water formations, it absorbs the sun's radiation unevenly. Two factors are necessary to specify wind: speed and direction.
Answer:
Ans 1) If the volume of the gas is kept constant , its pressure increases with the increase in temperature. For example, when the air is suck out of a bottle, the air present out side it exerts pressure in all possible directions of bottle . Due to this reason the bottle gets crushed.
Ans 2) This activity again confirms that air exerts pressure. Crumple a small piece of paper into a ball of size smaller than the mouth of an empty bottle. Hold the empty bottle on its side and place the paper ball just inside its mouth. Now try to blow on the ball to force it into the bottle.
Ans 3) To form a cyclone, warm, moist air over the ocean rises upward from near the surface. As this air moves up and away from the ocean surface, it leaves is less air near the surface. So basically as the warm air rises, it causes an area of lower air pressure below.
Ans 4) During a cyclone
Turn off all electricity, gas and water; unplug all appliances.
Keep your emergency kit close at hand.
Bring your family into the strongest part of the house.
Keep listening to the radio for cyclone updates.
If the building begins to break up, shelter under a strong table, bench or heavy mattress.
Ans 5) The wind is caused by differences in atmospheric pressure. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds. On a rotating planet, air will also be deflected by the Coriolis effect, except exactly on the equator.