What is a Simple Machine? Machines are used to reduce the amount of force required to do work. But you must apply this force over a greater distance. The amount of WORK stays the same

Inclined Plane A slope or a ramp. Any slanted surface used to raise a load from a lower level to a higher level. wikidave.wikispaces.com phy.cmich.edu

Examples: ramps for wheel chairs a ramp used by a workman to push a heavy load on wheels up into a truck an escalator an inclined plane was used to move huge stones to build the Egyptian Pyramids ramps to load luggage onto a plane

Advantage: Helps to move or raise heavy objects. Advantage: Lift with LESS FORCE… Disadvantage: but the distance over which it moves is greater.

http://www. sciencetech. technomuses http://www.sciencetech.technomuses.ca/english/schoolzone/Info_Simple_Machines2.cfm#pulley

Pulleys A simple machine. A wheel with a groove in it. A rope/cable goes into the groove.

Pulleys Can: Change direction of force Change amount of force The amount of WORK stays the same

Fixed Pulley Stays attached. Does NOT change the amount of force Only changes the direction of force. Easier to pull down than to pull up. The amount of WORK stays the same

The amount of WORK stays the same http://www.the-office.com/summerlift/pulleybasics.htm

Moveable Pulley The mass is attached to the pulley. The pulley moves on the rope.

Decreases the amount of force needed to move the mass. Disadvantage: You have to pull the load up The amount of WORK stays the same

The amount of WORK stays the same http://www.the-office.com/summerlift/pulleybasics.htm

What happens to the amount of work? Which pulley changes the direction of the force? Which pulley reduces the amount of force?