Simple Machines Simple Machines Wheel and axle Pulley

Simple Machines

Simple Machines • • • Wheel and axle Pulley Lever Inclined plane Wedge Screw

Work • Work is the transfer of energy from one system to another • Mechanical work is the product of the magnitude of force in the direction of displacement and the distance through which a body moves Displacement

Work • Work indicates that a force is exerted and is moving something • Simple machines make work easier Microsoft Office Clipart © i. Stockphoto

Wheel and Axle • Two connected circular objects of different diameters Microsoft Office Clipart Microsoft Office Clipart

Special Wheel and Axle • Gear – Wheel with teeth – Teeth of one gear push against teeth of another gear Microsoft Office Clipart Microsoft Office Clipart

Pulley • A wheel (and axle) with a rope running over it Microsoft Office Clipart Microsoft Office Clipart

Pulley • A pulley can change the direction of force • Multiple pulleys in combination can reduce the effort force to move an object 10 lb 80 lb 10 lb

Lever • A bar that is free to pivot around a fixed point Microsoft Office Clipart

Lever • Three components – Resistance Force – Effort Force – Fulcrum Resistance Effort Fulcrum

Lever • Three types – First Class • Fulcrum between effort and resistance forces • Effort and resistance forces in same direction Effort Resistance

Lever • Three types – Second Class • Resistance force between fulcrum and effort force • Effort and resistance forces in opposing directions Resistance Effort

Lever • Three types – Third Class • Effort force between fulcrum and resistance force • Effort and resistance forces in opposing directions Resistance Effort

Inclined Plane • Slanted surface used to raise an object Microsoft Office Clipart © i. Stockphoto Microsoft Office Clipart

Specialized Inclined Planes • Wedge • Screw Images from Microsoft Office Clipart

Wedge • Inclined plane that moves • A triangle shape with a sharp point • Can split, cut, tighten, or hold things together Microsoft Office Clipart Microsoft Office Clipart

Screw • Inclined plane wrapped around a shaft • Used to fasten things together or move things © i. Stockphoto Worm gear © i. Stockphoto Corkscrew conveyor © i. Stockphoto Parking garage ramp

References Microsoft, Inc. (2008). Clip art. Retrieved from http: //office. microsoft. com/en-us/clipart/default. aspx Wikipedia. Retrieved from http: //en. wikipedia. org i. Stockphoto. Retrieved from http: //www. istockphoto. com/index. php