WIND Flashcards
What is air pressure
Air pressure is the pressure exerted by air. air exerts pressure on all directions and all objects. the pressure exerted by air depends on temperature and altitude
give an example where air pressure is used in real life
tyres and balloons are made up of elastic material that expand when air or gas is pumped into them.when air is pumped into tyres/baloons the air pressure exerted by the air inside the tyres/baloons keeps them inflated and enables them to carry the vehicle.
what is the atmosphere
the atmosphere is an envelope of air that surrounds the earh
explain atmospheric pressure
the pressure exterted by the atmosphere on the earth due to the weight of the air is called atmospheric pressure.atmospheric pressure decreases with altitude.since we live on the lowest layer of atmosphere the pressure is the highest. the magnittiude of atmoshperic pressure on top of a mount is less than the pressure at sea level
explain expansion of air due to heating
the volume of a given amount of air depends on temperature.as the temperature increases the volume also increases as the particles move apart so air expands upon heating.air becomes lighter as it expands due to a decrease in its density so it rises up
what is wind and how is it formed
the flow of air in the atmosphere of the earth .when air on the surface of earth is heated by the sun it expands and creates a low pressure region below.air form nearby high pressure region flos into the low pressure regions and causes win. the hot air that rises up cools and sinks down.this continues and a cycleof air flow is formed which is called wind current.
explain how high speed wind reduces pressure
wind flowing over an region reduces the air pressure in that region.the faster the wind speed the lower the pressure,this was absorved by swisss mathamatecian and phycisist daniel bernoulli.
give 2 examples where high wind speed reduces the pressure
you can absorve that high wind speed reduces pressure by holding a piece of paper close to your mouth,blow on the pape rthe high wind speed reduces the air pressure over the paper. so the pressure below the paper is higher and pushes the paper up.so we can say that moving air can provide a lift
2.roofs get blown off due to wind. when high winds blow over the roofs there is lower pressure.so below the roof the pressure exerted by the air is so high that it lifts hthe roof up which then get nlown up
EXPLAIN HOW WIND CURRENTS AREFORED
wind currents are formed due to the uneven heating of the earth’s surface between the equator and the poles. the equilateral regions receive more sunlight than the polar regions so the air around this region gets heated ad rises. this creates a low-pressure region. cold air from the high-pressure regions on either side pf the equator up to the latitude of 30 flows into the low-pressure regions near the equator. the warm rises coool and sinks in the regions of latitude nearly 30 south and north of the equator. as the cool air sinks the area becomes a high-pressure region. once again wind flows from these high-pressure area regions to the equatorial and polar regions. as the flow towards yhr poles at regions of latitude 60 from the equator it meets the cold air from the poles and rises to create a low-pressure region in these areas. the cold air from the poles flows again to these low-pressure regions.
Explain the coriolis foce
due to the effect of the rotation of the earth, the wind flowing in the north hemisphere bends towards the right and the wind in the southern hemisphere bends towards its left (concerning an observer at the ground) this is due to the origin of a force known as Coriolis force which caused by the rotation of the earth about its axis. the direction of the Coriolis force in the northern hemisphere is towards the right and in the southern hemisphere it’s towards the left
what is wind speed and how do you measurre it
wind speed is the rate of flow of wind in the atmosphere of the earth.it measure by using a device called anemometer and expressed by km/h
hte commonly used anemometer is a cup anemometer.
it has 4 cups hoisted on a vertical pole at right angles to eavhother.when the wind blows the wind presses on the inner side of the cup rotating it.the speed with which it rotates depends on the speed of the wind.
what is direction of wind and how do you measure it
the direction of wind is determined by the direction from which the wind originates. it is found using devices like wind vane and wind stock.the wind vane consists of an arrow hoisted on a vertical rod or pole that can rotate. the rear part of the arrow is broad providing more surface area flr the wind. so the wind hits the rear part with more foce. The wind vain will align so that the pointed part of arrrow always points to the direction of the win. the wind is named according to the direction from which it flows.the wind flowing from the north is northley wind and flowing from the south is osuthley wind
