What is the minimum mass needed on a lever to raise a specific load?

The minimum mass needed on a lever to raise a specific load is indeed based on the lever arm lengths. In a lever system, the principle of moments states that for the lever to be in equilibrium, the clockwise moments about the fulcrum must equal the counterclockwise moments.

Mathematically, this is represented as:

[

\text{Force}_1 \times \text{Distance}_1 = \text{Force}_2 \times \text{Distance}_2

]

where Force refers to the weight of the masses on either side of the lever and Distance refers to the distance from the fulcrum to where each force is applied. The longer the lever arm on one side, the less force (or mass) is needed to balance a heavier weight on the other side. Therefore, the specific mass required is influenced by both the load being lifted and the distance from the fulcrum to where the load is applied.

Since the relationship between the weights and the distances from the fulcrum determines the effective balance of the lever, this shows clearly how the lever arm lengths play a crucial role in determining the minimum mass needed.