What is the difference between ideal mechanical advantage (ima) and actual mechanical advantage (ama)?

Ideal mechanical advantage would be from a device with the assumed probability that there is no friction, wear or flexion. It is the ratio of the force put out (load) to the effort (force put into the machine).

Actual mechanical advantage takes into consideration of friction, wear and flexion. It is the ratio of the effort output and the effort input.

Ideal mechanical advantage does not considers frictional losses of force into account whereas actual mechanical advantage does.

Explanation:

Mechanical advantage is the increase in the output force by a simple machine which is due to increased arm length on which the output is desired. This is in accordance with the law of conservation of energy and moments.

Mathematically give as;

where:

are the force due to load and effort respectively.

are the length of effort arm and load arm respectively.

Now the mechanical advantage:

In practical cases we are not able to take the full advantage of this multiplied force due to the frictional losses.

does anyone know or what?