Simple machines6 types of simple machines, mechanical advantage of each type and compound machines

What is a machine?

Machines make work easier by changing either the force, distance or direction of the force you exert.

Mechanical Advantage

(MA)= output force/input force

The # of times a machine increases a force

The 6 basic types of simple machines

Inclined planeWedgeScrewLeverWheel & axlePulley

Inclined Planeflat, sloped surface.

Mechanical advantage

Length of inclineHeight of incline 11 0.5

meters

4 metersMA =4 m/0.5 m= 2

Wedgea device that is thick at one end and tapers to a thin edge at the other end.

Mechanical advantage

Length of wedgeWidth of wedge

MA =?10 cm / 2 cm= 5

10 cm

2 cm

Screwsinclined plane wrapped around a cylinder.

Mechanical advantage

Length around the threadsLength of the screw

5 cm Thread length = 60 cmMA =60 cm / 5cm= 12

Leversa ridged bar that is free to pivot, or rotate, on a fixed point.

Mechanical Advantage Distance from fulcrum to input

force Distance from fulcrum to output

force

10 cm 50 cm

What is the mechanical advantage?MA = 50 cm/ 10 cmMA = 5

Classification of Levers

according to the location of the fulcrum relative to the input and output forces.

- Simple Machines

Simple Machines in the BodyMost of the machines in your body are levers that consist of bones and muscles.

Wheel and Axlemade of two circular objects fastened together that rotate about a common axis.

Pulleymade of a grooved wheel with a rope or cable wrapped around it.

Wheel and axle

Simple MachineMechanical Advantage

Example

Inclined planeLength of incline ÷ Height of incline Ramp

Radius of wheel ÷ Radius of axle Screwdriver

WedgeLength of wedge ÷ Width of wedge

Ax

ScrewLength around threads ÷ Length of screw Screw

LeverDistance from fulcrum to input force ÷ Distance from fulcrum to output force

Seesaw

PulleyNumber of sections of supporting rope Flagpole

Compound MachinesA compound machine is a machine that utilizes two or more simple machines.