Question

Aman and Sindhu are playing on a seesaw. Aman weighs $450N$ and Sindhu weighs $300N$. Aman is on one side sitting $3m$ away from the pivot. How far away must Sindhu sit (w.r.t pivot) to balance seesaw?

• A. $4m$
• B. $4.5m$
• C. $2m$
• D. $3.5m$

Answer 1

The correct option is B $4.5m$

Moment of force is given by the product of the force and its distance from pivot.

Moment of force produced by Aman:
$M_1=450N\times 3m=1350Nm$

Let the distance between pivot and Sindhu be $r$.
Moment of force produced by Sindhu:
$M_2=300r$

For seesaw to be in equilibrium, both the moments of force should be equal.
$300r=1350$
$r=4.5m$