CBSE Class 9 Answered

Pascal's law:

Pascal's law or Pascal's principle states that "a change in the pressure of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container. Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid. Difference of pressure due to a difference in elevation within a fluid column is given by:

              ∆P = ρ g (∆h)

Where

ΔP:  is the hydrostatic pressure (given in pascals in the SI system), or the                           difference in pressure at two points within a fluid column, due to the weight of the fluid;

ρ :       is the fluid density (in  kilograms per cubic meter in the SI system);

g :    is acceleration due to gravity (normally using the sea level acceleration due to  Earth’s gravity in meters per second squared);

Δh :    is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in meters in SI).

Use:

Used for amplifying the force of the driver's foot in the braking system of most cars and trucks, in artesian wells, water towers and dams.