Mechanical advantage

why do we use machines?

to make work easier

define work

force applied to an object and the distance it is applied through

how do simple machines change the work done?

transfer force from one place to another

What are the 6 simple machines?

Inclined Plane, Wedge, Screw, Lever, Wheel and Axle, and Pulley

what is mechanical advantage

ratio of output force divided by input force

Actual Mechanical Advantage (AMA)

output (resistance) force/ input (effort) force

Ideal Mechanical Advantage (IMA)

input (effort) distance / output (resistance) distance

why do engineers use AMA more than IMA

AMA is measurement of all forces acting on a system

mechanical advantage of an inclined plane

MA \= Length/hieght

mechanical advantage of a pulley

Ma\= \# of supporting ropes

mechanical advantage of a lever

IMA = effort distance / resistance distance

AMA = resistance force/effort force

what are the three parts of a lever

effort arm, resistance arm, and fulcrum

1st class lever

effort on one side load on the other both pushing down EX: scissors

2nd class lever

effort and load on same side of the fulcrum, load pushing down effort pushing up furthest away from the fulcrum EX: wheel barrel

3rd class lever

effort is closest to the fulcrum and load on the other end of the effort arm EX:broom

unit for work

joules