Two children want to balance horizontally on a seesaw. The first child is sitting one meter to the left of the pivot point located at the center of mass of the seesaw. The second child has one-half the mass of the first child. Where should the second child sit to balance the seesaw?

a. 1m to the right of the pivot
b. 0.5m to the right of the pivot
c. 4m to the right of the pivot
d. 2m to the right of the pivot

d. 2m to the right of the pivot

Explanation:

m1 = m

m2 = 0.5m

d1 = 1m

d2 = ?

from principle of moment,

CWM = ACWM

m × 1 = 0.5m × d2

d2 = m/0.5m

= 1/0.5

= 2m

The 2nd child will have to sit 2m to the right

The turning effect of a force is known as the moment. It is the product of the force multiplied by the perpendicular distance from the line of action of the force to the pivot or point where the object will turn.

The principle of moments states that when in

equilibrium the total sum of the anti clockwise

moment is equal to the total sum of the

clockwise moment.

When a system is stable or balance it is said to be in equilibrium as all the forces acting on the system cancel each other out.

In equilibrium

Total Anticlockwise Moment = Total

Total Anticlockwise Moment = TotalClockwise Moment