2. Pressure “Thrust”
A force can be applied on a
surface in any direction. If the
force is applied on a surface
in direction normal to the
surface, the force is called
thrust.
3. The Effect Of Thrust
The effect of thrust
depends on the area of
the surface on which it
acts. Smaller the area of
the surface on which a
thrust acts, largest is its
effect.
4. Factors affecting pressure
The Pressure on a surface depends on
the following two factors:
1. On the area of the surface on which
thrust acts.
2. On the magnitude of thrust acting on
the surface.
1.Dependence of pressure on the area of surface:
When you stand on sand, a thrust equal to your weight acts on a smaller area
and so exerts more pressure on sand, hence you sink more. But when you lie
down on sand, the same thrust acts on a large area.
6. Type of
pressure1.Liquid pressure
2.Atmospheric pressure
A solid exerts pressure on a surface due to its own
weight. They also exerts pressure on the container in
which they are kept .But a liquid exerts pressure not
only on the surface of its container at the bottom, but
also sideways, that is, in all directions.
7. Atmospheric
pressureLike liquid, gases also exert
pressure. Our earth is surrounded
by air to a height of air around the
earth is called the atmosphere.
Air has weight. The weight of air exerts the earth
thrust on unit area of the earth surface due to th
of air is called atmospheric pressure.