PLTW Mechanics and Simple Machines Vocabulary

Actual Mechanical Advantage

The ratio of the magnitude of the resistance and effort forces applied to a system.

belt

A continuous band of tough flexible material used to transmit motion and power within a pulley system.

chain

A series of usually metal links or rings connected to or fitted into one another and used to transmit motion and power within a sprocket system.

effort force

An external force applied to an object.

Efficiency

The percentage of the input work that is converted to output work

Friction

the resistance that one surface or object encounters when moving over another.

fulcrum

The fixed point around which a lever pivots

gear

A circular toothed object used to transfer rotary motion and torque through interlocking teeth.

ideal mechanical advantage

Ratio of distance traveled by the applied effort and resistance force within a system.

Idler Gear

A gear positioned between the driver and the driven gear used to change rotational direction.

lever

A rigid bar that is free to move around a fixed point

mechanism

The structure of or the relationship of the parts in a machine, or in a construction or process comparable to a machine.

moment

The turning effect of a force about a point equal to the magnitude of the force times the perpendicular distance from the point to the line of action from the force.

pitch

Distance between adjacent threads in a screw.

pulley

A type of lever that is a wheel with a groove in its rim, which is used to change the direction or multiply a force exerted by a rope or cable.

resistance force

Impeding effect exerted by one material object on another.

screw

a simple machine that consists of an inclined plane wrapped around a cylinder

simple machine

Any of various elementary mechanisms including the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw.

Sprocket

A toothed wheel whose teeth engage the links of a chain.

static equilibrium

A condition where there are no net external forces acting upon a particle or rigid body and the body remains at rest or continues at a constant velocity.

Technical Communication

Creating, designing, and transmitting technical information so that people can understand it easily and use it safely, effectively, and efficiently.

Torque

a force that causes rotation

wedge

A substance that tapers to a thin edge and is used for splitting, raising heavy bodies, or for tightening by being driven into something.

wheel and axle

Two different sized circular objects that are attached together and turn as one.