Experiment to Understand: Air Exerts Pressure Video Lecture | Class 7 Oxford Science: Chapter Notes, Worksheets & Tests

air exerts pressure air exerts pressure
all around us this phenomenon can be
noticed during flying of paper kites or
fluttering of flags let us conduct an
experiment for this you need a tin can
with a lid a tripod stand burner and
water fill half of the tin can with
water light the burner and place the
tripod stand above it please the can on
the stand and let the water boil now
extinguish the burner and carefully
close the can with its lid now place the
can under running water
observe that the cans shape gets
distorted do you know why this happens
this is due to the decrease in air
pressure inside the can when the can is
placed in running water due to the
process of condensation some steam of
the can gets converted into water this
decreases the air pressure inside the
can and becomes lesser than the air
pressure exerted on the can from outside
this compresses the can and the shape
gets distorted high-speed winds are
accompanied by reduced air pressure when
there is an increase in the wind speed
there is always reduced air pressure
that accompanies it we will see this
with an example take two balloons and
fill them up with a small quantity of
water now blow air into them and tie
both of them to a string with a gap of
10 centimeters doing them in the empty
space between the balloons blow air with
your mouth the balloons move slightly
towards each other the wind will blow
between the balloons reduces the air
pressure in that area
this makes the balloons more closer
towards each other