Discover - Sorting Simple Machine Systems



Whether you are working or playing, the tasks you need to complete can be real problems. For example, if you are on a sailboat, how do you get the sail raised quickly and easily without having to climb up the mast? Suppose you are constructing a tall building. How do you get the construction supplies to the top of the building? What if you were working on a loading dock and had heavy boxes to lift onto trucks? How would you do it quickly and safely? The solution to all these problems is to use simple machine systems. Combining levers, ramps, wheels, gears, pulleys, and spinning axles can overcome almost any problem. Sometimes two simple machines will perform the same task, but an engineer can decide which simple machine system is best suited to the task.





Engineering Connection

Another simple machine is the inclined plane, also called a ramp. The ramp solves many problems where heavy things have to be lifted, especially when it is combined with other simple machines.  For example, a wheel and axle cart makes rolling heavy boxes up a ramp onto a truck easier.  A ramp provides a force advantage for the same reason as lever, pulley, and gear systems.  By increasing the distance you move, less force is needed.  When you use a ramp, you need to move the boxes a longer distance, but you need less force than you would take to lift the boxes straight up.

 Notebook: How are wheel and axle, pulley, and gear systems different? How are they the same?

  1. Click here to download this activity.
  2. Complete the activity and check your answers below.
  3. Save your corrected work to your Machines Notebook.
Activity Links:
     

    Check Your Answers


    1. Wheel and Axle Systems:
    • These are really rotating levers
    • The large knob magnifies the force of the turning motion, making a shorter, but stronger turn at the axle.
    2. Pulley Systems:
    • Work by changing the direction of the effort force, and allowing you to use your body weight as effort force.
    • Single pulleys give a mechanical advantage of one, so they really just re-direct the effort force.
    • In general the more pulleys you have (set up properly), the more mechanical advantage you will have.

    3. Gear Systems:
    • Several toothed wheel and axles, connected either by their teeth, or a chain.
    • Smaller gears move faster, larger gears have more force.

    4. What do they have in common?
    • They can give mechanical advantage
    • They have axles
    • They have an effort force
    • The have a load