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Bellwork: 2-27-2014

Bellwork: 2-27-2014. List five simple machines that you or someone in your family uses to help make work easier around the house. Objectives. Differentiate between the six simple machines. (SPI 0707.11.1)

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Bellwork: 2-27-2014

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  1. Bellwork: 2-27-2014 • List five simple machines that you or someone in your family uses to help make work easier around the house.

  2. Objectives • Differentiate between the six simple machines. (SPI 0707.11.1) • Determine the amount of force needed to do work using different simple machines. (SPI 0707.11.2)

  3. 70. 2-Square Vocabulary • Complete the 2-square vocabulary activity in your scientist notebook with your group. Do the “yours” side for the 12 words/phrases above. • Complete the scenarios with your group. Write the explanations on your next blank page in your scientist notebook. • When you are finished, raise your hands and I will check your work. • Work hard, smart, and QUICKLY!!!

  4. Bellwork 2-28-14 • Get out Scientist Notebook and continue working on the 2-square vocabulary and scenarios.

  5. Objectives Differentiate between the six simple machines. (SPI 0707.11.1) Determine the amount of force needed to do work using different simple machines. (SPI 0707.11.2)

  6. Machine YOURS: textbook: • A machine is a device that makes work easier by changing the size or direction of a force. • Examples: wheelchair, scissors, chopsticks

  7. Simple Machines YOURS: textbook: • A machine or simple device without moving parts. • Examples: lever, pulley, wheel & axle, inclined plane, wedge, screw

  8. Work YOURS: textbook: • Work is the transfer of energy to an object by using a force that causes the object to move in the direction of the force. • Work is done on an object if two things happen: 1) the object moves as a force is applied, 2) the direction of the object’s motion is the same as the direction of the force. • Examples: pushing a ball up a hill

  9. Work or Not Work? or OR YES NO YES NO

  10. Force YOURS: textbook: • A push or a pull exerted on an object in order to change the motion of the object; force has size and direction. • Examples: people, bulldozer, static electricity

  11. Work Input/Work Output YOURS: textbook: • Work input is the work done on the machine. • Work output is the work done by the machine. • Examples: opening a paint can

  12. Lever YOURS: textbook: • A lever is a simple machine that has a bar that pivots at a fixed point, called a fulcrum. • Examples: first-class lever (see saw), second-class lever (wheelbarrow or soda bottle opener), third-class lever (lifting weights or hammering a nail)

  13. Three Classes of Levers

  14. Levers

  15. Pulley YOURS: textbook: • A simple machine that has a grooved wheel that holds a rope or a cable. • Examples: fixed, moveable, block and tackle

  16. Movable pulleys do increase force, but they also increase the distance over which the input force must be exerted. A fixed pulley and a movable pulley are used together; the mechanical advantage of a block and tackle depends on the number of rope segments. The pulley changes the direction of the force. Elevators make use of fixed pulleys.

  17. Pulleys Which of the pulley systems shown below will lift the weight using the least amount of effort force?

  18. Wheel & Axle YOURS: textbook: • A simple machine consisting of two circular objects of different sizes. • Examples: car’s wheel & axle, faucet

  19. Wheel & Axle Effort force applied to a wheel is ____________ when it is transferred to the axle because the axle travels a ___________ distance than the wheel. multiplied, longer divided, longer multiplied, shorter divided, shorter

  20. Inclined Plane YOURS: textbook: • A simple machine that is a straight, slanted surface; a ramp. • Examples: ramp or slide

  21. Inclined Plane

  22. Wedge YOURS: textbook: • A simple machine that is made up of two inclined planes and that moves; often used for cutting. • Examples: knife, axe, door stop

  23. Wedge Select the choice that best completes the following sentence. When an axe is used to chop wood, the axe blade acts as a wedge and changes the direction of the input force. the axe blade acts as a wedge and does not change the direction of the input force. the axe blade acts as a lever and does not change the direction of the input force. the axe blade acts as a lever and changes the direction of the input force.

  24. Screw YOURS: textbook: • A simple machine that consists of an inclined plane wrapped around a cylinder. • Examples: screw, light bulb

  25. Screws Which of the screws below requires the least amount of effort force to turn? X. Y. Z. W.

  26. Compound Machine YOURS: textbook: • A machine made up of more than one simple machine. • Examples: manual can opener

  27. YOURS: textbook: Mechanical Advantage It is 10 times easier to use a ramp to move a heavy object. A machine’s mechanical advantage is the number of times the machine multiplies force; how much easier it is to do the work using that specific machine. Examples:

  28. SCENARIOS

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