General Science: Physics of Machines and Fluids

Vocabulary-style flashcards covering the concepts of simple and compound machines, motion types, and fluid mechanics including density, pressure, and buoyancy.

Machine

A device that makes work easier by changing the size or direction of force.

Simple Machine

A machine containing one mechanical part that changes force or motion.

Compound Machine

A combination of two or more simple machines working together.

Efficiency

A measure of how well a machine converts input work into useful output work, calculated as $\text{Efficiency (\%)} = \frac{\text{Output Work}}{\text{Input Work}} \times 100\%$.

Mechanical Advantage (MA)

A measure of how much a machine multiplies the applied force.

Translational Motion

Motion that moves in a straight line where all parts move the same distance and direction.

Rotational Motion

Motion that occurs around a fixed axis or point.

Force

A push or pull that changes motion.

Work

A force causing movement in the same direction.

Lever

A rigid bar that pivots on a fulcrum to move a load.

Pulley

A wheel with a groove that uses a rope to lift or move loads.

Inclined Plane

A sloping surface that makes it easier to raise or lower loads.

Wheel & Axle

A wheel attached to an axle where both rotate together.

Screw

An inclined plane wrapped around a cylinder.

Wedge

Two inclined planes joined to form a sharp edge.

Hydraulic System

A system that uses pressurized liquid to transmit force and perform work.

Fluid Mechanics

The study of the behavior of fluids.

Fluid Statics

The study of fluids at rest.

Fluid Dynamics

The study of fluids in motion.

Aerodynamics

The sub-field of fluid dynamics focusing on gases in motion.

Hydrodynamics

The sub-field of fluid dynamics focusing on liquids in motion.

Pneumatic Systems

Systems that use gases to transmit force and perform work.

Density ($\rho$)

Mass per unit volume, calculated using the formula $\rho = \frac{m}{V}$ with the SI unit $kg/m^3$.

Pressure ($P$)

Force applied perpendicular to an area, expressed as $P = \frac{F}{A}$ with the SI unit Pascal ($Pa$).

Pascal's Principle

A principle stating that pressure applied to an enclosed fluid is transmitted equally in all directions; expressed as $\frac{F_1}{A_1} = \frac{F_2}{A_2}$.

Archimedes' Principle

The principle stating that the buoyant force is an upward force exerted by a fluid equal to the weight of the fluid displaced by the object ($F_b = \rho g V$).

Buoyant Force ($F_b$)

The upward force exerted by a fluid on an object measured in Newtons ($N$).

Floating

A condition occurring when the buoyant force is greater than or equal to the object's weight ($F_b \geq W$) or when the object is less dense than the fluid.

Sinking

A condition occurring when the object's weight is greater than the buoyant force ($W > F_b$) or when the object is denser than the fluid.