Rotational Motion Question 75
Question: ABC is an equilateral triangle with O as its centre. $ F _1,F _2 $ and $ F _3 $ represent three forces acting along the sides AB, BC and AC respectively. If the total torque about O is zero then the magnitude of $ F _3 $ is
[AIPMT (S) 2012]
Options:
A) $ F _1+F _2 $
B) $ F _1-F _2 $
C) $ \frac{F _1+F _2}{2} $
D) $ 2(F _1+F _2) $
Show Answer
Answer:
Correct Answer: A
Solution:
-
If we take clockwise torque
$ \tau ={\tau _{F _1}}+{\tau _{F _2}}+{\tau _{F _3}} $
$ 0=F _1r+F _2r+F _3r $
$ F _3=F _1+F _2 $
