System
A group of parts that work together to achieve a certain goal.
Physical System
A group of physical parts that work together to perform a specific function.
Social System
A group of humans or other organisms joining together to perform tasks or form relationships.
Force
Any push or pull.
Input
The force, energy or raw materials put into a system.
Output
The task or purpose that a system performs.
Side Effects
The unintended or undesired outputs of a system.
Systems Thinking
Taking into account the inputs, outputs or side effects of a system.
Simple machine
a device that requires a single force to work.
Fulcrum
the pivot of a lever.
Load arm
the part of a lever that extends to the load.
Effort arm
The part of a lever that extends to where the pressure is applied from.
Input force
the effort force applied to a lever.
Output force
The force the lever applies to the load.
Load force
The force the input force has to overcome to cause any movement.
Inclined plane
For the moving of heavy objects between vertical planes.
Wedge
Used to stop the movement of a machine.
The screw
Used to drill through materials or to move liquid materials.
The lever
Used to move a load (usually heavy) with ease.
Wheel and axle
Used to transfer small force into big actions, change types of force.
The pulley
Used to lift heavy objects with ease.
Magnitude
the quantity of force.
Newton
the unit used to measure forces (N).
Friction
the force that resists objects rubbing or sliding past one another.
Static friction
The force that holds a motionless object where it is.
Sliding friction
The force that acts like a brake when one surface slides over another.
Lubricant
a substance that reduces friction.
Mechanical advantage (MA)
the ratio of output force to input force of a given machine.
Ideal Mechanical advantage
the MA if all output force was converted to input force, not possible in real-world applications.
Actual Mechanical advantage
The MA in real applications, equal to the ideal MA minus the force lost to friction, slippage, etc.