simple machines. wheel and axle pulley lever inclined plane wedge screw
TRANSCRIPT
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
Microsoft Office Clipart
Microsoft Office Clipart © iStockphoto
Wheel and Axle
• Two connected circular objects of different diameters
Microsoft Office Clipart
Microsoft Office Clipart
Microsoft Office Clipart
Microsoft Office Clipart
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
Microsoft Office Clipart
Microsoft Office Clipart
Microsoft Office Clipart
Pulley
• A wheel (and axle) with a rope running over it
Microsoft Office Clipart
Microsoft Office ClipartMicrosoft Office Clipart
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 10 lb
10 lb
80 lb
10 lb
Lever
• A bar that is free to pivot around a fixed point
Microsoft Office Clipart
Microsoft Office Clipart
Microsoft Office Clipart
Lever
• Three components– Resistance Force– Effort Force– Fulcrum
ResistanceEffort
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
© iStockphoto
© iStockphoto
Microsoft Office Clipart
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
Microsoft Office Clipart
Microsoft Office ClipartMicrosoft Office Clipart
Screw
• Inclined plane wrapped around a shaft
• Used to fasten things together or move things
Corkscrew conveyor
Worm gear
Parking garage ramp© iStockphoto
© iStockphoto
© iStockphoto© iStockphoto
References
Microsoft, Inc. (2008). Clip art. Retrieved from http://office. microsoft.com/en-us/clipart/default.aspx
Wikipedia. Retrieved from http://en.wikipedia.org
iStockphoto. Retrieved from http://www.istockphoto.com/index.php