Two children sit balanced on a seesaw with the pivot point located at the center of the seesaw. if the first kid has a mass of 36 kg and sits at a distance of 1.2 meters from the pivot, where should the second kid of mass 24 kg sit to balance the see-saw?

To solve the problem it is necessary to apply the concepts of Torque and equilibrium.

The Torque is defined as:

Where

F= Force

d = Distance

In this particular case, the force is caused by the weight of both children.

In turn, when there is equilibrium, the two torques must be equal therefore

Replacing with our values

Re-arrange to find

Therefore the distance that the second kid should sit to balance the see-saw is 1.8m from the pivot.

wavelength variability is the right one

the part of the wave he is travelling on is the crest