Question

On a see saw , two children of weights 30 kgf and 50 kgf are sitting on one side of it at distances 2m and 2.5 m respectively from its mid dle. Where should a man of weight 74 kgf sit to balance it​

Answer 1

x=2.5m

Explanation:

Let, the two children by sitting on the left arm .They will produce anti- clock wise moment due to their weights about the middle point.

Total Anti-clock wise moment

$=30kgf ×2m +50kgf×2.5m$

$=60kgf m +125 kgf m$

$=185kgf m$

To balance it, the man should sit on the right arm to produce a clock wise moment.Let his distance from the middle be x m .

Then,

Anti-clock wise moment = Clockwise moment

$=> 185 = 74x$

$=> x = \frac{185}{74}m$

$=> x =2.5m$(on the the other side)