Frequently Asked Questions
Mechanical properties of fluids describe how liquids and gases respond to forces, including their ability to flow, transmit pressure, resist motion, and show surface effects like viscosity and surface tension.
A fluid is a substance that cannot resist shear stress in static condition and continuously deforms under even a small tangential force. Liquids and gases are fluids.
Pressure is the normal force exerted per unit area by a fluid on any surface in contact with it, given by P = F/A.
Pressure increases with depth according to P = P0 + ?gh, where ? is density, g is acceleration due to gravity, and h is depth.
Pascal’s law states that pressure applied to an enclosed fluid is transmitted equally and undiminished to all parts of the fluid and the container walls.
Pascal’s law is applied in hydraulic lifts, hydraulic brakes, hydraulic presses, and hydraulic jacks.
Buoyant force is the upward force exerted by a fluid on an immersed body, opposing the weight of the body.
A body immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by it.
Objects float if the buoyant force equals or exceeds their weight, usually when their average density is less than the fluid density.
Viscosity is the internal resistance of a fluid to the relative motion between its layers.
The coefficient of viscosity is the force per unit area required to maintain a unit velocity gradient between two parallel layers of a fluid.
Stokes’ law states that the viscous force on a small sphere moving in a fluid is F = 6p?rv.
Terminal velocity is the constant maximum velocity attained by a body falling through a viscous fluid when net force becomes zero.
Terminal velocity is given by v = (2r²(? - s)g)/(9?).
Surface tension is the property of a liquid surface that makes it behave like a stretched elastic membrane.