A board of mass M = 2.0 kg serves as a seesaw for two children. Child
A has a mass of 30 kg and sits 2.5 m from the pivot point, P (his center
of gravity is 2.5 m from the pivot). At what distance x from the pivot
must child B, of mass 25 kg, place herself to balance the seesaw?
Assume the board is uniform and centered over the pivot.