Question

which example of levers would require the least amount of force to move the box? e. lever a f. lever b g. lever c h. they are all first class levers which require the same amount of force.

Explanation:

Step1: Recall lever principle

The mechanical advantage of a lever is given by the ratio of the effort - arm length to the load - arm length ($MA=\frac{l_{effort}}{l_{load}}$). The greater the mechanical advantage, the less force is required to move the load. For a first - class lever, the fulcrum is between the effort and the load.

Step2: Analyze the levers

In Lever A, the effort - arm is the shortest among the three levers. In Lever B, the effort - arm is of medium length. In Lever C, the effort - arm is the longest. According to the formula $MA=\frac{l_{effort}}{l_{load}}$, when the load is constant, a longer effort - arm results in a greater mechanical advantage.

Step3: Determine the answer

Since Lever C has the longest effort - arm, it will have the greatest mechanical advantage and will require the least amount of force to move the box.

Answer:

G. Lever C