International Sports Sciences Association (ISSA) Trainer Practice Exam

A second-class lever is most comparable to which of the following?

1. A seesaw

2. A wheelbarrow

3. A pair of scissors

4. A stapler

The correct answer is: A wheelbarrow

A second-class lever is characterized by the load being positioned between the fulcrum and the effort applied. This configuration allows for a mechanical advantage, as the effort can lift a larger load with less force than that exerted by the load itself. A wheelbarrow exemplifies this concept perfectly: the wheel acts as the fulcrum, the load (such as soil or construction materials) is placed in the middle, and the user exerts effort at the handles to lift and move the wheelbarrow. This setup shows how the second-class lever can effectively make lifting easier by allowing a person to apply a smaller force over a longer distance to move a heavier load. In contrast, a seesaw is an example of a first-class lever, where the fulcrum is positioned in the middle with the load and effort on either end. A pair of scissors functions as a shearing mechanism and exemplifies a first-class lever as well, and a stapler involves a different mechanism altogether, often a compound lever system rather than a simple one. The wheelbarrow, as a second-class lever, highlights the efficiency of this lever type in lifting and transporting heavy objects with ease.