simple machines n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Simple Machines PowerPoint Presentation
Download Presentation
Simple Machines

Loading in 2 Seconds...

play fullscreen
1 / 43

Simple Machines - PowerPoint PPT Presentation


  • 131 Views
  • Uploaded on

Simple Machines. Simple Machines make work easier for us. What is work? Work occurs when a force causes an object to move in the direction of the force. This means that if you are simply holding a heavy object, you are not doing any work.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Simple Machines


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Simple Machines

    2. Simple Machines make work easier for us. • What is work? • Work occurs when a force causes an object to move in the direction of the force.

    3. This means that if you are simply holding a heavy object, you are not doing any work. • Even if an object is moving, work is only done if the force is in the direction of motion.

    4. Arms Pulling Gravity No work is being done on the suitcase.

    5. The formula to calculate work:WORK = FORCE x DISTANCE Units of measurement:Force – newtonsDistance – metersWork – newton-meter = joule

    6. Power Is a measure of how fast work is done.POWER = WORK TIME Units of measurement:Work – joulesTime – secondsPower – joules/second = watt

    7. Simple Machines • Machines are devices that make work easier by changing the SIZE or DIRECTION of a FORCE. • Machines do not reduce the amount of work for us, but they can make it easier.

    8. The Force-Distance Trade-off • A machine can reduce either the FORCE or DISTANCE required to do work, but not both. • If FORCE is DECREASED, the DISTANCE the force is exerted must INCREASE.

    9. Six types of Simple Machines • Inclined Plane • Lever • Wheel & Axle • Pulley • Screw • Wedge

    10. Examples

    11. More Examples

    12. ORGANIZER

    13. ORGANIZER

    14. Levers • A lever is a simple machine made with a bar free to move about a fixed point called a fulcrum. There are three types of levers.

    15. LOAD LOAD Input Force Output Force • A first class lever has the fulcrum between the INPUT FORCE and the OUTPUT FORCE. Fulcrum

    16. Examples:

    17. LOAD Input Force • In a second class lever, the LOAD is between the FULCRUM and the INPUT FORCE. Fulcrum

    18. Examples of Second Class Levers

    19. LOAD • In a third class lever, the INPUT FORCE is between the FULCRUM and the LOAD. Output Force Fulcrum Input Force

    20. Example of a Third Class Lever

    21. Mnemonic Device to Remember the 3 classes of Levers: FLEA

    22. F L E FULCRUM LOAD EFFORT FORCE FORGET THE “A”

    23. 2nd 3rd 1st F L E

    24. LOAD 1st class lever: the FULCRUM is between the LOAD and the EFFORT FORCE 1st Effort Force F L E Fulcrum

    25. LOAD 2nd class lever: the LOAD is between the FULCRUM and the EFFORT FORCE 2nd F L E Fulcrum Effort Force

    26. LOAD 3rd class lever: the EFFORT FORCE is between the FULCRUM and the LOAD 3rd F L E Fulcrum Effort Force

    27. Pulleys • A pulley is a simple machine made with a rope, belt or chain wrapped around a grooved wheel.

    28. A movable pulley is attached to the object you are moving. • A fixed pulley changes the direction of the applied force. ( Ex. Raising the flag ) .

    29. Inclined Plane • An inclined plane is a simple machine with no moving parts. • It is simply a straight slanted surface. example: a ramp

    30. Wheel and Axle • The wheel and axle must move together to be a simple machine. • Sometimes the wheel has a crank or handle on it. • Examples: roller skates and doorknobs.

    31. Wedge • A WEDGE is made of two inclined planes put together. • Example: A knife blade

    32. Screw • A screw is an inclined plane that is wrapped around a shaft. • Example: Bottle cap

    33. Mechanical Advantage OUTPUT FORCE • Mechanical advantage tells you how many times a machine multiplies force. = Mechanical Advantage INPUT FORCE (Input force means the same as effort force)

    34. If a lever has a MECHANICAL ADVANTAGE of 5, the output force is 5 times the input force. • Therefore, the INPUT FORCE must travel 5 times the distance of the OUTPUT FORCE

    35. load We can calculate the mechanical advantage of a lever by comparing the effort arm to the load arm. Length of Effort Arm MA lever = Length of Load Arm

    36. The Load Arm is often called the Resistance Arm

    37. LOAD Lever with Mechanical Advantage of 1 Length of Effort Arm = Length of Load Arm

    38. LOAD A Mechanical Advantage of 1 means that the OUTPUT FORCE is the same as the INPUT FORCE. Input Force Why would you want this type of lever? Output Force

    39. LOAD 5 times Distance AB Distance BC Lever with Mechanical Advantage of 5 C B A =

    40. LOAD A Mechanical Advantage of 5 means that the OUTPUT FORCE is 5 times the INPUT FORCE. Input Force The input force must move through a distance 5 times greater than the distance the load moves. Output Force

    41. load We can calculate the mechanical advantage of an inclined plane by comparing the length of the plane to the distance the load is lifted. Length of Plane MA inclined plane = Height the load is lifted

    42. load Example: 8 feet 2 feet 8 feet 4 MA inclined plane = = 2 feet

    43. Summary • Simple machines are "simple" because most have only one moving part. • Machines do not reduce the amount of work for us, but they can make it easier. • "Work" is only done when something is moved in the direction of a force. • Work is the product of effort and distance.