A seesaw has a heavier friend on one side and a lighter friend on the other. Where should the lighter friend sit to balance the seesaw? Why?

The lighter friend should sit further away from the fulcrum (the pivot point in the middle of the seesaw) to balance the seesaw. This is because the seesaw follows the principle of moments in physics, which states that for an object to be balanced, the total clockwise moment about a point must be equal to the total anticlockwise moment about the same point.

In simpler terms, the weight of an object multiplied by its distance from the pivot point (moment) on one side of the seesaw must be equal to the weight of the object multiplied by its distance from the pivot point on the other side.

So, if the heavier friend is closer to the fulcrum, the lighter friend can balance the seesaw by sitting further away from the fulcrum. This increases the lighter friend's distance, and therefore their moment, to match the heavier friend's larger weight but smaller distance.