What is a fluid?
A substance that can flow and conform to the shape of its container; includes liquids and gases.
Define a 'Fluid System'.
Any system involving the flow of a fluid (gas or liquid).
What is 'Density'?
Mass per unit volume, often denoted by the symbol $\rho$.
Define an 'Open System' in fluid mechanics.
A system where fluid can flow in and out.
Define a 'Closed System' in fluid mechanics.
A system where fluid cannot flow in or out.
What is 'Viscosity'?
A measure of a fluid's resistance to flow.
What happens when the pressure on a balloon decreases?
The volume of the balloon increases (Boyle's Law).
What is the effect of increased density on buoyant force?
Increased density results in a greater buoyant force, assuming volume and gravitational acceleration remain constant ($F_b = \rho V g$).
What happens when the buoyant force on an object is greater than its weight?
The object rises.
What is the effect of increased temperature on the viscosity of a liquid?
Generally, increased temperature decreases the viscosity of a liquid.
What is the effect of increased temperature on the viscosity of a gas?
Generally, increased temperature increases the viscosity of a gas.
What are the key differences between liquids and gases?
Liquids: Relatively incompressible, have a definite volume. | Gases: Compressible, no definite volume.
Differentiate between an 'Object' and a 'System' in the context of fluid mechanics.
Object: A single physical entity or a group of components combined in a specific way. | System: A group of objects that interact with each other and their environment.
Compare Open and Closed Fluid Systems.
Open System: Allows fluid to flow in and out, mass is not conserved within the defined boundaries. | Closed System: Does not allow fluid to flow in or out, mass is conserved within the defined boundaries.
Compare fresh water and salt water.
Fresh water: Lower density. | Salt water: Higher density due to dissolved salt.
