Question

Define the three kinds of a lever. Draw diagrams to show the position of fulcrum, load and effort in the kinds of levers.

Answer 1

A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. The kinds of lever are:

• First-Class Levers

1. In the first-class lever, the fulcrum is located between the effort and the load.
2. The seesaw is a good example of the first-class lever.
3. Crowbars, shears, and pliers are common examples of this class of lever.

• Second-Class Levers

1. The second-class lever has the fulcrums at one end, the load is at the middle and the effort is applied at the other end.
2. Example is a wheelbarrow where the effort moves a large distance to lift a heavy load, with the axle and wheel as the fulcrum.
3. Nutcrackers are also an example of a second-class lever.

• Third-Class Levers

1. When the effort is between the load and the fulcrum, then it is a third-class lever.
2. Broom, barbecue tongs and a fishing rod are some examples of the third-class lever.
3. In a third-class lever, the mechanical advantage is low.