Simple machines. Levers. Technology.

1. Simple machines. levers Technology, 1º ESO By Joaquín Ballester

2. SIMPLE MACHINE A simple machine is a mechanical device that changes the direction or magnitude of a force. They are the simplest mechanisms that use mechanical advantage to multiply force. A simple machine uses a single applied force to do work against a single load force. The work done on the load is equal to the work done by the applied force. They can be used to increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the input force is called the mechanical advantage. Font: Wikipedia

3. SIMPLE MACHINES

4. LEVERS A lever is a rigid object that is used with an appropriate fulcrum or pivot point to multiply the mechanical force (effort) that can be applied to another object (load).

5. LAW OF THE LEVER

6. CLASSES OF LEVERS

7. EXERCISES John weighs 90 Kg and Jane weighs 60 Kg. They are both seating on a seesaw. If John is seated 10 feet away from the pivot, how far should Jane be from the fulcrum of the seesaw to be well balanced? 1 foot = 0,3048 metres Peter wants to move a 400 lb rock with a 69 cm crowbar. He puts the fulcrum 9 cm from the rock. How much force must he use to move the rock? 1 pound = 0.45 kilograms

8. EXERCISES Whateffortwouldberequiredtoraise a load of 300N using a 5m leverifthefulcrumis at 1 metre fromtheforcethatweapply?