Flashcards Chapter 11

What are the four states of matter?

Solid, liquid, gas, and plasma

What is the difference in shape and volume between solids, liquids, and gases?

Solids have definite shape and volume

Liquids have definite volume but take the shape of their container, Gases have no definite shape or volume and expand to fill the container

What are plasmas?

Plasmas are ionized gases with no definite shape or volume

What qualifies a material as a fluid?

A material is considered a fluid if it yields to shearing forces and flows easily

What is a shearing force?

A force that acts parallel to a surface, causing layers to slide past each other

How do solids and fluids respond differently to shearing forces?

Solids may resist or break under shear; fluids continuously deform and flow under shear

What does viscosity measure?

The resistance of a fluid to flow (low viscosity = flows easily; high viscosity = resists flow)

What is density?

Density is the amount of mass per unit volume of a substance

Write the formula for density.

\rho = m/V

What are the SI units of density?

Kilograms per cubic meter (kg/m³)

What is the density unit commonly used in chemistry and biology?

Grams per cubic centimeter (g/cm³)

How many kg/m³ is equal to 1 g/cm³?

1000 kg/m³

What is pressure?

Pressure is force applied per unit area

Write the formula for pressure.

P= F/A

What are the SI units of pressure?

Pascals (Pa), where 1 Pa = 1 N/m²

Name three other units commonly used for pressure.

psi (pounds per square inch), mmHg (millimeters of mercury), atm (atmosphere)

How many Pascals equal 1 atmosphere?

101,325 Pa

Why does pressure increase with depth in a fluid?

Due to the weight of the fluid above

Write the formula for pressure variation with depth.

P = \rho g h

What does each symbol represent in P = \rho g h ?

ρ = fluid density, g = gravity acceleration (9.8 m/s²), h = depth

Does this formula include atmospheric pressure?

No, it only accounts for pressure due to the fluid

How do you calculate absolute pressure in an open container?

P_{absolute}=P_{atm}+\rho gh

What does Pascal’s Principle state?

A change in pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid and container walls

Write the equation that represents Pascal’s Principle in hydraulic systems.

F_1/A_1 = F_2/A_2

What type of fluids work best in hydraulic systems?

Incompressible fluids, like hydraulic oil or water

How does a hydraulic lift multiply force?

A small force on a small piston produces a large force on a larger piston due to pressure transmission

What is gauge pressure?

Pressure measured relative to atmospheric pressure; it can be positive or negative

What is absolute pressure?

Total pressure including atmospheric pressure; always positive

Write the formula connecting absolute pressure and gauge pressure.

P_{abs}=P_{g}+P_{atm}

Why does a flat tire have a gauge pressure reading of zero?

Because the pressure inside equals atmospheric pressure; gauge reads relative to atmosphere

What is Archimedes’ Principle?

The buoyant force on an object equals the weight of the fluid displaced

Write the formula for buoyant force.

F_B = \rho_f V_s g

What determines if an object floats or sinks?

The object’s density compared to the fluid’s density

What happens if \rho_{object} < \rho_{fluid}

The object floats

What is specific gravity?

The ratio of the density of an object to the density of water

What is cohesion in liquids?

Attraction between like molecules within a liquid.

What is adhesion?

Attraction between unlike molecules, such as water and glass

What causes surface tension?

Cohesion among surface molecules creating a net inward force

Write the formula for surface tension force.

F=γL

What is capillary action?

Movement of liquid in a narrow tube due to cohesion and adhesion

What unit is surface tension measured in?

Newtons per meter (N/m)

How does capillary action depend on tube radius?

Smaller radius increases capillary rise