Compound Machines By Sarah Owens

Table of Contents Introduction Examples Pictures Games

Examples Scissors-The part that you hold to cut with is a lever. The part that cuts is a wedge. Can opener-The arm are 2 levers, gears help turn the can.

Picture

Games http://www.edheads.org/activities/simple-machines/ Click on click here to start. When you get in the game click on the tool shed.

Pulleys and Screws By Tori Contoudis

Intro A compound machine consists of two or more simple machines put together. In fact, most machines are compound machines. Compound machines can do more difficult jobs than simple machines alone. Their mechanical advantage is far greater, too. Some examples are a pair of scissors and a bicycle.

Pulleys Helps move things to higher places easily You have to pull the rope that goes on the pulley 2 times as far as you want the object to go. A pulley is a simple machine Circular shaped object with elevated sides so the rope that goes around it doesn’t fall of. The number of pulleys decides the mechanical advantage of the system. Pulley video

Screws A shaft with a helical groove around it It is a simple machine Screws make the job of keeping things together There are tons of different screws Was first created by a Greek mathematician around 200 b.c. The closer the threads the more mechanical advantages

Wedges and pulleys

contents Pulley Wedge Video of pulleys and levers

Pulley A pulley is made from a wheel and a rope. It is used to make lifting easier. A single pulley changes the direction of the lifting force. For example, if you are lifting a heavy object with a single pulley anchored to the ceiling, you can pull down on the rope to lift the object instead of pushing up. The same amount of effort is needed as without a pulley, but it feels easier because you are pulling down. If you add a second pulley, the amount of effort to lift the heavy object is much less -- half as much. However, you will have to pull the rope further. A double pulley can help you to lift objects you could never lift without it. back

Wedge The wedge is the twin of the inclined plane. It does useful work by moving. The inclined plane always remains stationary. This simple machine consists of a pair of inclined planes set face-to-face, that can sustain relative sliding or rolling motion. By moving one plane relative to the other, a wedge is capable of building up enormous force in a direction perpendicular to that of the moving wedge. back

Lever, and the wheel & axle By: Krizia Wearing

Table of contents

The Lever What is a lever? A lever is a rigid bar that is free to pivot, or rotate, about a fixed point.

Examples of Lever An example of a lever is a can opener. The opener rests against the edge of the can, which acts as the fulcrum. The tip of the opener is under the lid of the can. When you push down, you exert an input force on the handle and the opener pivots about the fulcrum.

The Wheel & Axle What is the Wheel & Axle? The wheel and axle is a simple machine made of two circular or cylindrical objects that are fastened together and that rotate about common axis.

Example of The Wheel & Axle