Simple machines & work no work assessment intro

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Simple machines & work no work assessment intro

  1. 1. NOW THE WEIGHTS ARE BEING GENTLY LOWERED TO THE GROUND
  2. 2. YOU ARE PUSHING ON THECAR, BUT IT IS NOT MOVING
  3. 3. YOU ARE PUSHING THE You areCAR UPHILL, BUT IT IS pushingMOVING DOWNHILL the car uphill, but it is moving downhill
  4. 4. YOU CARRY A 1GALLON JUG OFMILK ACROSSTHE ROOM.
  5. 5. YOU DRAG A 5GALLON JUG OFWATER ACROSSTHE ROOM.
  6. 6. YOU PULL A WAGON DOWN THE SIDEWALK.
  7. 7. YOU SIT IN THE WAGON AS ITROLLS DOWN THE SIDEWALK
  8. 8. You areholding a heavy case of paper.
  9. 9. You arerunning asfast as you can down the track.
  10. 10. You aresitting at your desk for 2 hoursmemorizing a hard poem for class.
  11. 11. Definition of work:A force applied to an object in the same direction that the object moves to cover some distance. Lowering weights down is not work because though you are exerting a force(F) it is in the opposite direction of the movement (d)
  12. 12. W=F•dW is Work. It is measured in Joules (metric) Foot-pounds (english) F is force or weight. It can be measured in Newtons or Pounds d is the distance an object moves that is being acted upon.
  13. 13. Is work being done? Weight = 315 lbs. Distance weight was moved = Volunteer Work = ???A POWER LIFTER RAISING THE WEIGHTS UP INTO THE AIR
  14. 14. THE SAME POWER LIFTER HOLDING THE WEIGHTS UP
  15. 15. NOW THE 150LB WEIGHTS ARE BEINGGENTLY LOWERED 45 INCHES TO THE GROUND
  16. 16. YOU ARE PUSHING ON THECAR, BUT IT IS NOT MOVING
  17. 17. YOU ARE PUSHING THE You areCAR UPHILL, BUT IT IS pushingMOVING DOWNHILL the car uphill, but it is moving downhill
  18. 18. You areholding a heavy case of paper.
  19. 19. YOU CARRY A 1GALLON JUG OFMILK ACROSSTHE ROOM.
  20. 20. YOU DRAG A 5GALLON JUG OFWATER ACROSSTHE ROOM.
  21. 21. YOU PULL A WAGON DOWN THE SIDEWALK.
  22. 22. YOU SIT IN THE WAGON AS ITROLLS DOWN THE SIDEWALK
  23. 23. You arerunning asfast as you can down the track.
  24. 24. You aresitting at your desk for 2 hoursmemorizing a hard poem for class.
  25. 25. WE CAN MAKE WORK EASIER TO DO BY USING“SIMPLE MACHINES” There are 6 simple machines
  26. 26. 1. LEVER: TRANSMIT FORCE THROUGH A RIGID BAR, WHICH PIVOTS ON AN AXIS.
  27. 27. 2. WHEEL & AXLE: TAKING A LEVER AND MOVING IT IN ACOMPLETE CIRCLE. THE AXLE MUST MOVE WITH THEWHEEL AS IT TURNS. IF NOT, IT’S CALLED A PULLEY.
  28. 28. 3. PULLEY: A SIMPLE MACHINE THAT CHANGES DIRECTIONOF LINEAR FORCE, BY USING A WHEEL THAT SPINS ON ANAXLE OR HUB.
  29. 29. 4. INCLINED PLANE, RAMPS: A SLOPED SURFACE THATALLOWS OBJECTS TO BE TRANSPORTED VERTICALLYWITHOUT DIRECTLY LIFTING THEM.
  30. 30. 5. WEDGE: A SIMPLE MACHINE WITH A LARGE ENDTAPERING TO A THIN EDGE USED FOR SEPARATINGOBJECTS OR SECURING THEM.
  31. 31. 6. SCREW: A WEDGE OR INCLINED PLANE THATMOVES AROUND A PIVOT POINT
  32. 32. Simple Machines I.D. Activity (1 minute per station to identify)•NUMBER AND NAME EACH OBJECT•LIST THE SIMPLE MACHINES IN THE OBJECT IF ANY ORLIST WAYS YOU CAN MAKE IT WORK LIKE A SIMPLEMACHINE IF IT ISN’T ONE

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