Question

Study the diagram alongside and answer the following questions.

1. What kind of lever is shown in diagram?
2. Derive ideal mechanical advantage of this lever.
3. Give two examples of this lever.

Answer 1

a. It is a Class III lever (or third-order lever).

The effort (E) is located in the middle, between the fulcrum (F) and the load (L).

b. According to the Principle of Levers:

Load (L) × Load Arm (FB) = Effort (E) × Effort Arm (FA)

\[ \frac{L}{E} = \frac{FA}{FB} \]

Since Mechanical Advantage (M.A.) is defined as \[ \frac{\text{Load}}{\text{Effort}} \]:

\[ \text{Ideal M.A.} = \frac{\text{Effort Arm } ({FA})}{\text{Load Arm } ({FB})} \]

Here, the Effort Arm is always shorter than the Load Arm, so its M.A. is always less than 1.

c. Two examples are forceps and a fishing rod.