Fluids Unit Test Study Guide

Fluid

Materials that flow.

Viscosity

The thickness or thinness of a fluid.

Flow Rate

Measures how quickly fluids move.

Cohesion

The attraction between particles of the same substance.

Adhesion

The attraction between particles of different substances.

Density

The mass per unit volume of a substance.

Buoyancy

The ability of an object to float in a fluid.

Buoyant force

The ability of a fluid to support an object floating in or on it.

Neutral buoyancy

When the buoyant force is equal to the weight of an object.

Displacement

To move something out of its place in fluids by pushing water or air aside.

Compression

The reduction in volume of a substance due to applied pressure.

Hydraulics

Using liquid under pressure to transmit force in a system.

Pneumatics

The use of compressed gas to transmit force in a system.

What are the three states of matter?

Solid, Liquid, Gas.

How do particles behave in a solid?

Tightly packed, vibrating in place with a fixed shape and volume.

How do particles behave in a liquid?

Close together but can move past each other, taking the shape of their container.

How do particles behave in a gas?

Far apart, moving quickly in all directions and expanding to fill any container.

Solidification

Change from liquid to solid with heat removed.

Melting

Change from solid to liquid with heat added.

What is the difference between evaporation and boiling?

Evaporation occurs at the surface at any temperature; boiling occurs throughout the liquid at a specific temperature.

How does viscosity affect flow rate?

Higher viscosity results in lower flow rate.

What factors affect flow rate?

Temperature, pressure, surface friction, particle size.

Flow rate calculation formula

Flow rate = volume/time.

Density formula

Density = mass/volume.

Weight on Earth formula

W = mg.

What happens to fluid density when temperature decreases?

Density increases as temperature decreases due to particles moving closer together.

Why does a denser substance sink?

It has more mass per unit volume compared to a less dense substance.

How did Archimedes test the purity of the crown?

He measured its water displacement compared to pure gold.

Why are liquids less compressible than gases?

Liquid particles are already close together, while gas particles have more space.

Pascal's Law

Pressure applied to an enclosed fluid is transmitted equally in all directions.

Common hydraulic system components

Pump, Valves, Cylinders.

Example of hydraulic systems

Car brakes, excavators.

Example of pneumatic systems

Air brakes, dentist drills.

What are some negative environmental fluids?

Oil spills, industrial waste, pesticides.

Impact of oil spills on wildlife

Harmful to marine life, pollutes water and soil, requires costly cleanup.