MachinesHow to Work

Smarter, Not Harder

I. What is a Machine?

A. Machine is anything that helps us do work.B. They multiply or change the direction of force

C. Mechanical advantage: measures the efficiency of the machineD. In the real world, no machine is 100% efficientE. This is because of friction

II. Simple MachinesA. There are 6 types of simple machines.

1. Lever: bar that pivots around a fulcrum

a. 1st classb. 2nd classc. 3rd class

2. Pulley: grooved wheel and some sort of cord or rope

3. Wheel & Axle: round object that rotates around a rod

4. Ramp: an inclined plain

5. Wedge: triangular shape used for splitting things

6. Screw: inclined plain wrapped around a central core

II. What are Compound Machines?

A. combination of any 2 or more simple machinesB. Examples:

1. axe2. wheel barrow