In a scenario where a second-class lever is used, which device serves as the classic example?

• A. A wheelbarrow
• B. A crowbar
• C. A screwdriver
• D. A seesaw

Answer: (A)

In a second-class lever, the load sits between the fulcrum and the effort. The wheelbarrow fits this perfectly: the wheel acts as the fulcrum at one end, the load sits in the tub between the wheel and the handles, and you apply force at the handles. Because the effort arm from the fulcrum to your hands is longer than the load arm from the fulcrum to the load, you get a mechanical advantage and can lift heavier loads with less effort. A seesaw places the fulcrum between the effort and the load, making it a first-class lever, not second-class. Crowbars and screwdrivers are typically used as first-class levers in their common applications. So the wheelbarrow is the classic example of a second-class lever.