Chapter 24: FORCE
is either contact [friction, muscular] or non contact
[magnetic, electrostatic, gravitational, pressure]
is inversely related to area. So smaller the area, larger
the pressure for the same force.
Pressure and its real applications
Nail is easily pushed into wood from its pointed end than
its head, tools for cutting have a sharp edge, shoulder
bags have broad straps, and porters carrying heavy loads
wrap a cloth on their head.
large wooden plank placed on top of the circus performer
keeps his ribs from breaking when an elephant steps on
above activities regulate pressure by changing the
of astronauts are filed with air to counter the
pressure exerted by the body otherwise their blood vessels
would burst as there no pressure on the moon.
altitudes, pressure is low so liquids boil at low
temperature. Hence we use pressure cookers to cook.
autoclaves to sterilize medical instruments,
waters boiling point is increased by putting higher
pressure on it.
Pressure by liquids
also exert equal pressure at the same depth. Air also
exerts a great pressure on organisms but our body counters
the pressure so we don’t feel anything.
are treated as in-compressible, whenever pressure
is applied on any part of a liquid it is transmitted in
all directions equally and undiminished. This principle is
used in hydraulic lifts and brakes.
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