In the given figure the tension in the string OB is 30N. Find the weight 'W and the tension in the string OA.

Explanation

Let `T_(1)` and `T_(2)` be the tensions in the strings OA and OB respectively

According to lami.s theorem
`(T_(1))/(sin 90^(@)) = (T_(2))/(sin 150^(@)) = (W)/(sin 120^(@)) (T_(2) = 30N)`
on solving `w = 30sqrt(3)N` and `T_(1) = 60 N`