Hydraulics, Buoyancy, Archimedes’ Principle – Vocabulary Flashcards

Vocabulary flashcards covering fluid properties (fluid, density, mass, volume), Pascal’s Principle and hydraulic systems, fluid pressure concepts, buoyancy, Archimedes’ Principle, and real-world examples such as syringes, straws, cargo ships, and life jackets.

Fluid

Any substance that can flow and alter its shape.

Density

Mass per unit volume of a substance.

Mass

The amount of matter in an object.

Volume

The amount of space that an object or fluid occupies.

Blaise Pascal

17th‑century French mathematician and physicist who formulated Pascal’s Principle.

Pascal’s Principle

A change in pressure applied to an enclosed, incompressible fluid is transmitted undiminished to all parts of the fluid and to the walls of its container.

Pressure

Force per unit area.

Enclosed fluid

A fluid confined in a closed system where pressure can be increased more easily than in an open system.

Hydraulic system

A mechanical system that uses pressurized fluid to transmit and amplify forces.

Pump

Device that pressurizes the fluid in a hydraulic system.

Fluid reservoir

Container that stores the hydraulic fluid in a system.

Tubes and valves

Pathways and controls for fluid flow in a hydraulic system.

Pressure transmission

In a hydraulic system, pressure is transmitted (undiminished) through the fluid to do work on actuators.

Pressure increases with depth

Fluid pressure grows with depth because of the weight of the fluid above.

Buoyant Force

The upward force on an object in a fluid.

Archimedes’ Principle

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

Floating vs. sinking (density)

An object will float if its average density is less than the surrounding fluid; it sinks if denser.

Mass vs. volume in buoyancy

A floating object displaces fluid whose weight equals the object's weight (mass-based); a sinking object displaces fluid equal to its entire volume.

Cargo ships

Steel ships float by displacing a large volume of water; hulls are hollow to lower average density.

Life jackets

Foam or air pockets lower the wearer’s average density, aiding flotation.

Syringe pressure

Pushing the plunger increases pressure; a small tip area yields higher pressure, forcing fluid out.

Straw pressure

Sucking air lowers the pressure inside the straw, so fluid pressure in the drink pushes it up.