Question

On a see-saw, two children of masses 30 kg and
50 kg are sitting on one side of it at distances 2m
and 2.5. m respectively from its middle. Where
should a man of mass 74 kg sit to balance it?
GIVE ME THE SOLUTION WITH DIAGRAM
​

Answer 1

Answer:

Total Anti-clockwise moment = 30 kgf x 2m + 50kgf x 2.5 m

= 60 kgf m + 125 kgf m = 185 kgf m

To balance it, the man should sit on the right arm (to produce clockwise moment). Let his distance from the middle be x m. Then

Clockwise moment = 74 kgf x X m = 74x kgf m

By the principle of moments,

Anti-clockwise moment = Clockwise moment

185 = 74x

or x = 185/74m

= 2.5 m (on the other side