Question

A single fixed pulley is equivalent to a :

• A. first order lever
• B. second order lever
• C. third order lever
• D. complex machine

Answer 1

Answer: (A)

first order lever

$\text{Solution}:$

1. A single fixed pulley is really a first class lever with equal arms.

2. In Figure, the arm from point “R” to point “F” is equal to the arm from point “F” to point “E” (both distances being equal to the radius of the pulley).

3. When a first class lever has equal arms, the mechanical advantage is 1. Thus, the force of the pull on the rope must be equal to the weight of the object being lifted.

$\text{Hence A is correct option}$