Honors Physical Science

Work formula

Force\*Distance (work comes first)

MA formula

Output/input (Output first)

Efficiency formula

Output/input\*100 (Output first)

MA of lever formula

dif/dof (dif MA dof)

MA of ramp

Length/Height or Output/Input (L MA H)

Work

Exerting force on an object causing it to move

Machine

A device that makes work easier or more efficient

Input force

The force you exert on an object (effort force)

Output force

The force exerted by the machine (resistance force)

Mechanical advantage

Ratio of force produced by machine to force applied to it

Efficiency

How well the machine works as a percent

Inclined plane

A flat, slanted surface

Wedge

A device that’s thick on one and gets smaller towards the next end

Screw

An inclined plane wrapped around a cylinder

Lever

A rigid bar that rotates or turns on a point called the fulcrum

Classes of levers

First class, second class, third class

First class lever

Multiplies force when distance from fulcrum to input force is greater than fulcrum to output force. Pliers, scissors

Second class lever

Multiplies force. Door, nut crackers

Third class lever

Multiplies distance. Baseball bat, fishing pole, shovel

Wheel and axle

Made of two circular cylindrical objects fastened together and rotates together on an axis

Pulley

A grooved wheel with a rope or steel cable wrapped around it

Types of pulleys

Fixed, movable, pulley system

Three ways a machine makes work easier

Multiply force, distance or changing direction

MA of multiplying force

Greater than 1

MA of multiplying distance

Less than 1

MA of changing direction

Is 1