Mechanical properties of fluids

What is the definition of fluid?

A substance that can flow, including liquids, gases, and plasmas.

What are the properties of fluids?

They do not oppose deformation, they can flow, and they take the shape of their container.

What is hydrostatics?

The branch of physics that deals with the properties of fluids at rest.

What is pressure in a fluid?

The normal force exerted by a fluid at rest per unit surface area.

What is the S.I. unit of pressure?

N/m², which is also known as Pascal.

What does Pascal’s law state?

The pressure applied at any point in an enclosed fluid at rest is transmitted equally and undiminished to every point of the fluid.

What is the relationship between absolute pressure and gauge pressure?

The difference between absolute pressure and atmospheric pressure is called gauge pressure.

What factors influence atmospheric pressure?

Atmospheric pressure is highest at sea level and decreases with altitude.

What is the formula for pressure due to a liquid column?

P = pgh, where P is pressure, p is density, g is acceleration due to gravity, and h is height.

What is surface tension?

The tendency of liquid surfaces to shrink into the minimum surface area, caused by cohesive forces.

What is the formula for surface tension?

Surface Tension = Force / Length.

What is the effect of temperature on surface tension?

Surface tension decreases with an increase in temperature.

What occurs during capillary action?

The rise or fall of liquid in a narrow tube due to adhesive and cohesive forces.

What is the critical velocity in fluid dynamics?

The velocity beyond which a streamline flow becomes turbulent.

What is Reynolds number used for?

It is a dimensionless number that indicates the nature of fluid flow; laminar flow for R < 1000, turbulent for R > 2000.

What factors affect viscosity?

Viscosity is affected by temperature and the nature of the fluid.

What does Stoke's law describe?

The viscous force acting on a small sphere falling through a viscous medium is proportional to its radius and velocity.

What parameters are involved in the equation of continuity?

The conservation of mass principle, stating that mass flow rate is constant in a steady flow.

What is Bernoulli's equation?

It states that the total mechanical energy of the flowing fluid remains constant; P + 1/2mv² + mgh = constant.

What results from increased speed in a fluid according to Bernoulli's principle?

A decrease in pressure within the fluid.

How does a hydraulic lift work?

It uses Pascal's law to lift heavy objects using a small applied force.

What is flow line in fluid mechanics?

The path that an individual particle of fluid follows.

What is the significance of streamline in fluid mechanics?

A curve that is tangent to the velocity of the fluid at every point.

What is capillary rise?

The upward motion of liquid in a narrow space due to adhesive forces being stronger than cohesive forces.

How does surface tension affect the shape of liquid drops?

Liquid drops tend to be spherical due to surface tension minimizing surface area.

What is the impact of impurities on surface tension?

Impurities can either increase or decrease surface tension depending on their solubility.

What is the relationship between pressure and height in a liquid column?

Pressure increases with depth due to the weight of the liquid above.

What guarantees fluid stability during capillary action?

The balance between adhesive forces, cohesive forces, and gravitational forces.

What happens in turbulent flow?

Every particle of fluid moves in different directions irrespective of the direction of the overall flow.