Wind Mill

The blades of a windmill sweep out a circle of area A. (a) If the wind flows at a velocity upsilon perpendicular to the circle, what is the mass of air passing through it in time t? (b) What is K.E. of the air ? (c) Assume that the wind mill converts 25% of the wind's energy into electrical energy , and that A=30m^(2), upsilon=36km//h and the density of air is 1.2kg//m^(3) . What is electrical power produced ?

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term 'work'. (a) Suma is swimming in a pond. (b) A donkey is carrying a load on its back. (c ) A wind -mill is lifting water from a well. (d) A green plant is carrying out photosynthesis. (e ) An engine is pulling a train. (f) Food grains are getting drired in the Sun. (g) A saliboat is moving due to wind energy.

Look at the activites listed below. Reason out whether or not work is done in the light of your understanding of the term 'work'. (a) Suma is swimming in a pond. (b) A donkey is carrying a load on its back. (c ) A wind -mill is lifting water from a well. (d) A green plant is carrying out photosynthesis. (e ) An engine is pulling a train. (f) Food grains are getting drired in the Sun. (g) A saliboat is moving due to wind energy.

The first Cotton Mill in India was set up as a spinning mill in 1854 in _______.

Which vitamin is more in milled rice?

Where was the first Cotton Mill in India established ?