Simple and Compound Machines

A set of vocabulary flashcards covering simple and compound machines, including their definitions, classes, examples, and mathematical formulas for mechanical advantage.

Machine

Any device that makes work easier by changing the magnitude or direction of force without reducing the total work done.

Work Formula

The formula used to calculate work is $Work = Force \times Distance$.

Simple Machine

A basic mechanical device with few or no moving parts that helps make work easier, such as a lever or a pulley.

Lever

A rigid bar that rotates around a fixed point called the fulcrum.

Fulcrum

The fixed point around which a lever rotates.

1st Class Lever

A lever where the fulcrum is located in the middle; examples include a seesaw, crowbar, and scissors.

2nd Class Lever

A lever where the load is located in the middle; examples include a wheelbarrow, nutcracker, and bottle opener.

3rd Class Lever

A lever where the effort is located in the middle; examples include tweezers, a fishing rod, and the human forearm.

Wheel and Axle

A large wheel attached to a smaller axle where turning one causes the other to rotate, multiplying force known as torque.

Wheel and Axle MA Formula

The Mechanical Advantage is calculated as $MA = \frac{\text{Radius of Wheel}}{\text{Radius of Axle}}$.

Pulley

A grooved wheel with a rope or cable used to lift heavy loads.

Fixed Pulley

A type of pulley that changes the direction of force and has a Mechanical Advantage ($MA$) of $1$.

Movable Pulley

A type of pulley that multiplies force and has a Mechanical Advantage ($MA$) of $2$.

Compound Pulley (Block & Tackle)

A combination of fixed and movable pulleys where the Mechanical Advantage ($MA$) is equal to the number of rope segments.

Inclined Plane

A flat surface tilted at an angle that raises objects using less force over a longer distance.

Inclined Plane IMA Formula

The Ideal Mechanical Advantage is calculated as $IMA = \frac{\text{Length of Slope}}{\text{Height}}$.

Wedge

Two inclined planes joined together used to split, cut, or separate materials, such as a knife, axe, or chisel.

Screw

An inclined plane wrapped around a cylinder that converts rotational motion into linear motion.

Screw IMA Formula

The Ideal Mechanical Advantage is calculated as $IMA = \frac{\text{Circumference}}{\text{Pitch}}$, where pitch is the distance between threads.

Compound Machine

A machine made of two or more simple machines working together, such as a bicycle, wheelbarrow, or can opener.

Mechanical Advantage (MA) Formula

The general formula for Mechanical Advantage is $MA = \frac{\text{Output Force}}{\text{Input Force}}$.

IMA

Stands for theoretical Ideal Mechanical Advantage.

AMA

Stands for real-world Actual Mechanical Advantage.

Lever Group vs. Inclined Plane Group

The two primary classifications for the six simple machines used in engineering designs.