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Simple Machines. Guided Reading and Study. Inclined Plane. 2. Flat, sloped surface 3. IMA : length / height 4. The following are true: a) Input force less than output force b) A ramp is an example d ) Allows you to exert a force over a longer distance
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Simple Machines Guided Reading and Study
Inclined Plane • 2. Flat, sloped surface • 3. IMA: length / height • 4. The following are true: • a) Input force less than output force • b) A ramp is an example • d) Allows you to exert a force over a longer distance • 5. The larger (longer) the incline (less steep) the less input forceis needed to move an object
Wedge • 6. Thick at one end and tapers to a thin edge at the other end • Changes direction of the force • Examples: axe, zipper, knife, teeth… • 7. True – A wedge is an inclined plane (or 2 back to back) that can move • 8. True – longer, thinner wedges have a higher MA
Screw • 9. An inclined plane wrapped around a cylinder (Examples: screw, bottle cap (lid), curving parking ramp) • Multiples force (you input less force over a larger distance), can also change the direction of force • 10. The spiral inclined plane forms the threadsof a screw • 11. The input force is applied to the top of the screw. As the screw turns the threads exert on output force on the wood.
Lever • 12. A rigid bar that pivots or rotates around a fixed point. • 13. The fixed point that a lever pivots around is called the fulcrum
Lever 14. The following are true • a) A lever increases the effect of your input force • b) There are 3 different types of levers • c) A lever changes the direction of your input force
Lever • 15. • Fulcrum
Lever • 16. 2nd Class 1st Class 3rd Class
Lever • How levers make work easier depends on which class lever is being used. • 1st class: changes direction, can multiply force or distance • 2nd class: multiplies force • 3rd class: multiplies distance
First Class Lever Input force Output force Fulcrum
Second Class Lever Input force Output force Fulcrum
Third Class Lever Output force Input force Fulcrum
Lever • 17. • IMA: distance from effort (IF) to fulcrum distance from load (OF) to fulcrum
Wheel and Axle • 18. 2 circular objects fastened together that rotate around a common axis. The circle with the larger radius is the wheel • If input is turning the wheel: multiplies force • If input is turning the axle: multiplies distance • Examples: Steering wheel, screw driver, door knob
Wheel and Axle • 19. IMA = radius of wheel radius axle
Pulley • 20. Made of a grooved wheel with a rope or cable wrapped around it. • IMA: number of segments of rope that support the load • Examples are found on: flag poles, sail boats, construction cranes • 21. Type that changes the direction of input force = fixed pulley • 22. IMA of 2: moveable pulley • There are also block and tackle pulleys
Simple Machines in the Body • 23. Most of the levers in the body consist of bones and muscles • 24. Your muscles are attached to your bones by tough connective tissue called tendons • 25. In a living lever in your body the joint near where the tendon is attached to the boneacts as the lever’s fulcrum
Simple Machines in the Body 3rd Class Lever! • 26. Output Force Input Force Fulcrum
Simple Machines in the Body • 27. Incisors are wedges • 28. When you bite down on something, the wedge shape of your teeth produces enough force to break what you’re biting in half, just as an ax is used to split a log.
Compound Machines • 29. A machine that is made up of two or more simple machines. • 30. You must know the mechanical advantage of each simple machine utilized in the compound machine. The IMA of a compound machine is the product of the IMAs of the simple machines making up the compound machine.