how orientation of mountains of india does help us from cold polar winds
Answers
An individual gas molecule weighs almost nothing;
however, the atmosphere as a whole has
considerable weight and exerts an average pressure of
1034 grams per square centimeter (14.7 lb/sq in.) on
Earth’s surface. The reason why people are not crushed
by this atmospheric pressure is that we have air and water
inside us—in our blood, tissues, and cells—exerting an
equal outward pressure that balances the inward pressure
of the atmosphere. Atmospheric pressure is important
because variation in pressure within the Earth–atmosphere
system creates our atmospheric circulation and thus plays
a major role in determining our weather and climate. It is
the differences in atmospheric pressure that create our
winds. Further, the movement of the winds drives our ocean
currents, and thus atmospheric pressure works its way into
several of Earth’s systems.
In 1643, Evangelista Torricelli, a student of Galileo,
performed an experiment that was the basis for the
invention of the mercury barometer, an instrument that
measures atmospheric (also called barometric) pressure.
Torricelli took a tube filled with mercury and inverted it in
an open pan of mercury. The mercury inside the tube fell
until it was at a height of about 76 centimeters (29.92 in.)