Aboy and a girl are balanced on a massless seesaw. the boy has a mass of 60 kg and the girl's mass is 50 kg. if the boy sits 1.5 m from the pivot point on one side of the seesaw, where must the girl sit on the other side for equilibrium

1.8m

Explanation:

Using the principle of moment to solve the question which states that the sum of clockwise moment is equal to the sum of anticlockwise moments.

The boy moves in the clockwise direction towards the pivot while the girl moves in the anticlockwise direction towards the pivot.

Since moment = force × perpendicular distance

CW moments = 60×1.5 = 90Nm

ACW moments = 50×x = 50x

Equating both moments to get 'x'

90 = 50x

x =9/5

x = 1.8m

This shows that the girl must sit 1.8m from the other side for equilibrium.: