What is the fulcrum in the see-saw?
The fence-rail on which it rests, is the fulcrum.
What is the power in the see-saw?
The power is the boy on one end of the lever.
What is the weight in the see-saw?
The weight is the boy on the other end of the lever.
How do children play at see-saw?
By pushing against the earth with their feet, the arms of the lever are alternately forced to rise and fall in the air, thus making a see-saw.
Where must the fulcrum be when the two boys are of the same weight?
The fulcrum must be under the middle of the lever.