Wind

A wind is a simply flow of a huge amount of air usually from high pressure area to low pressure area.we find winds may be calm,gentle,moderate or strong.we can find different names of these winds in different countries. speed of the winds can be measured by using anemometer,rotating cups and propellers. CALM AIR:these are generally called as light wind.these are not enough ,even to fly a feather kite.speed of calm air is >2 km/hr.. Calm air will be noticed by smoke rising vertically from a chimney they have Beaufort number zero. GENTLE BREEZE:leaves and small twigs would move constantly with the gentle breeze.speed of this air is 12 to 20 km/hr. They Are called gentle moderate winds in the USA .they have Beaufort number three. MODERATE WINDS:they are enough to fly a kite and keep it going higher and higher.they can create moderate waves on the seas and can make trees whistle.speed of the whistle air is. Moderate winds have speed of about 20 to 38 km/hr. STRONG WINDS:strong winds also called as gale in some countries.they can make strong waves on seas and break off the branches of trees.gale winds can rip off roofs of buildings.speed of the strong winds is 62 to 74 km/hr. They have a Beaufort number of 8.