Levers - Key Information

The formulas shown here are the same as those shown before. We simply replaced the term L1/L2 with MA (mechanical advantage).

Try to understand and internalize the following information, because it will be used in later sections quite extensively.

1. L1 is always measured from the fulcrum to the point where the effort is applied. In the examples, shown so far it was fairly clear. But later on you’ll come across some instances where it may not be so clear. As long as you understand this basic concept you’ll do OK.

2. L2 is always measure from the fulcrum to the point where the weight acts.

3. For a lever to multiply the input force, L1 must be greater than L2.

4. In simple terms, MA for a lever tells us the force multiplication capacity of a lever. If a lever has an MA equal to 10, then it will magnify the applied force by 10.

5. Energy output is always less than the energy input. There are always some frictional losses. But for our purposes (to simplify) we ignore the losses and consider the input energy equal to the output work.