For the following simple see-saw calculate

The mechanical advantage (assume the lever is 100% efficient

The mechanical advantage of a see-saw is calculated by taking the ratio of the distance from the pivot point to the effort force (input force) divided by the distance from the pivot point to the load force (output force).

Let's assume the distance from the pivot to the effort force is 2 meters and the distance from the pivot to the load force is 1 meter.

Mechanical Advantage = Effort Distance / Load Distance
Mechanical Advantage = 2 meters / 1 meter
Mechanical Advantage = 2

Therefore, the mechanical advantage of the see-saw is 2. This means that the input force applied to the see-saw will be twice as large as the output force.