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Explore the different types of machines, including levers, inclined planes, wedges, screws, wheel and axles, and pulleys. Learn about their functions and examples of each type. Discover how compound machines are formed by combining two or more simple machines.
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Sci. 4-3 Types of Machines Pages 98- 105
A. All machines are constructed from 6 simple machines: lever, inclined plane, wedge, screw, wheel and axle, and pulley.
B. Lever- a bar that pivots at a fixed point called a fulcrum
1st class lever- the fulcrum is between the input force and the load. ( changes direction of force) • examples: seesaw, hammer pulling nail
2)2nd class lever- the load is between the fulcrum and the input force. Examples: wheel barrow, screwdriver on paint can
3) 3rd class lever- the input force is between the fulcrum and the load example- hammer striking nail
Inclined Plane- a straight slanted surface. A smaller input force is used over a longer distance. • 1) mechanical advantage of an inclined plane is calculated by dividing length by height
Wedge- a double inclined plane that moves (doorstops, plows, axe heads, & chisels) • 1)mechanical advantage of a wedge is length / thickness
E. Screws- an inclined plane that is wrapped in spirals. (lids, bolts)
F. Wheel and Axle- 2 circular objects of different sizes. (Doorknobs, wrenches, ferris wheels, screwdrivers, steering wheel)
2) Movable pulleys- attached to object (load) being moved. (does not change the directions of the force)
3) Block and tackles- fixed pulley and movable pulleys used together
H. Compound Machine- a machine that is made of two or more simple machines