Simple Machines FoldablePay attention

Simple MachinesSimple machines assist us in doing work by

creating a mechanical advantage.They do not change the amount of work;

they lower the effort force

There are 6 types of simple machines: lever, inclined plane, pulley, wedge, screw, and wheel and axle.

Most machines are a combination of two or more simple machines.

Inclined PlaneInclined planes are ramps.The length of the ramp is the effort

distance (de), while the height of the ramp is the resistance distance (dr).The weight of the object is the

resistance force.The force you apply is the effort force.The length of the ramp is always greater

than the height.

PulleysPulleys consist of a supporting cable and a

rotating wheel.Pulleys change the size, direction, or both of

the input force.An easy way to determine the mechanical

advantage of a pulley is to count the number of strings supporting the weight.The weight is the resistance forceThe distance the weight is lifted is the resistance

distance.The actual distance you pull the cable is the

effort distance.

LeversLevers consist of an arm that rotates around a

fixed point known as the fulcrum.

There are 3 classes of levers.

The effort distance is measured from the fulcrum to where the effort force is applied.

The resistance distance is measured from the fulcrum to where the weight (resistance force) is located.