6 Simple Machines

Introduction

Six Simple Machines Pulley Wedge Wheel and Axle Lever Inclined Plane Screw Pulley   A wheel with a grooved rim in which a rope can run and so change the direction of a pull. It is a simple machine that is used to raise weights. Wedge   A piece of wood or metal tapering to a thin edge, used in splitting or separating. Wheel and Axle   Axle on which a wheel is fastened, used to lift weights by winding a rope onto the axle as the wheel is turned. Lever   A bar which turns on a fixed support called a fulcrum and is used to transmit effort and motion. 3 Classes of Levers First-Class Lever Second-Class Lever Third-Class Lever First-Class Lever The fulcrum is between the effort and the resistance Motion in direction opposite effort Second-Class Lever Resistance between effort and fulcrum Motion in same direction as effort Third-Class Lever Effort between resistance and fulcrum Motion in same direction as effort. Inclined Plane   Plank or other plane surface set at an acute angle to a horizontal surface. Screw   A cylinder with an inclined plane wrapped around it and fitting into a threaded cylindrical hole. Screws are used in jacks to lift heavy loads.

Vocabulary Terms

Pulley Wedge Wheel and Axle Lever First-Class Lever Second-Class Lever Third-Class Lever Inclined Plane Screw

Review Questions

Related Internet Links

Inventors Toolbox, The Elements of Machines