1. Types of Simple Machines

2. Warm Up? What is work? What is a machine? What does a machine do?

3. WORK Work is done when a force causes an object to move in the direction of the force. For work to be done…the object MUST move in the SAME direction as the force Open your books to page 211…. Work = F x d

4. MACHINES A machine is a device that makes work easier by changing the SIZE or DIRECTION of the force. Force or distance can increase, but when one increases the other decreases! Open your books to page 218! Using a machine does not change the amount of work…just how it is done! Work that you do on a machine is called INPUT Work that is done by the machine is called OUTPUT

5. What is a machine made of? ALL MACHINES ARE MADE UP OF ONE OR MORE SIMPLE MACHINES. THERE ARE 6 DIFFERENT SIMPLE MACHINES

6. The Lever

7. a solid bar that rotates or turns around a fixed point called the fulcrum.

8. Types of levers Levers with different arrangements have different uses….there are three types of levers….. –FIRST CLASS LEVERS –SECOND CLASS LEVERS –THIRD CLASS LEVERS

9. Lever Parts Each lever has 3 parts: –Input force (what you put in) –Output force (load/object you are working on) –Fulcrum : pivot point

10. 1 st Class Lever The FULCRUM (pivot point) is located between the INPUT and OUTPUT forces. Use this type of lever to change the direction and size of the force

11. 2 nd Class Lever The OUTPUT is between the INPUT and the FULCRUM. The fulcrum is at one end of the lever. Use this lever to increase the output force.

12. 3 rd Class Levers The INPUT is between the OUTPUT and the FULCRUMN. Use this lever to reduce the distance over which the force is applied or to increase speed.

13. The Pulley

14. The Pulley p.224 Pulleys are related to levers A pulley has a grooved wheel that holds a rope or cable. A pulley changes the direction of the force There a 3 types of pulleys

15. The Fixed Pulley p.224 Is attached to something that doesn't move such as the ceiling or wall) Allows you to pull down to move something up. To lift something 2 meters, pull down 2 meters Elevators are fixed pulleys

16. Moveable Pulley p.224 Moveable pulleys are attached to the object they are moving. A moveable pulley does not change the direction of the force, but the size of the force. You need only half the force to lift the load, but you must pull the rope twice the distance

17. Block and Tackle p.224 A block and tackle is when a fixed and moveable pulley are used together.

18. The Inclined Plane

19. The Inclined Plane p.226 a slanted surface that does not move An inclined plane reduces the force needed by increasing the distance Used to reduce the force needed to overcome the force of gravity when lifting or lowering a heavy object.

20. The Screw

21. The Screw p.227 a ramp wrapped around a central cylinder A Screw has two (2) parts: –The Body – Cylinder Post –The Thread – Inclined Plane wrapped around the cylinder. –Reduces the force by increasing the distance

22. The Wedge

23. The Wedge an inclined plane that tapers to a sharp edge The wedge used to increase force. The material remains in place while the wedge moves through it. Wedges can be forced between two things to hold them tightly together, like nails or a doorstop. Wedges can be used to split, cut or fasten.

24. The Wheel & Axle

25. The Wheel & Axle p.225 a wheel connected to a rigid pole The Wheel & Axle consists of a circular objects rotating around an axle. The wheel is always the larger of the 2 objects.