Simple Machines

How do simple machines work? What do they actually do?

One thing that they do not do is to create less work for you. The best you can hope for when using a simple machine is that the work done using the machine is the same that it would have been without using the machine.

Look below to see how this works with an incline. Press the button to view how much work must be done without using the ramp then press the buttons for different sizes of ramps. See how the amount of work changes.

So simple machines make it easier to do work by reducing the force. Using the same examples above we can see how much less force you use when using the machine. This is called the mechanical advantage.

As you can see the mechanical advantage can be calculated by using the distance input/distance output. This is called TMA or Theoretical Mechanical Advantage.
The mechanical advantage can also be calculated by using the force output / force input. This is called AMA or Actual Mechanical Advantage.
In the real world, the AMA will always be less than IMA due to friction. The AMA is the actual amount the force is lessened by and the TMA is the amount the force would be lessned by without friction.
Friction means that the Efficiency of any machine will be less than 100% in the real world. Click Here to see how to calculate efficiency.

Look Here for Practice Problems: Simple Machines Problem Set

       
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