Kinematics Question 560
Question: A particle is moving in a vertical circle.The tensions in the string when passing through two positions at angles$ 30^{o} $ and $ 60^{o} $ from vertical (lowest position) are $ T _{1} $ and $ T _{2} $ respectively.then[Or it’ssa JEE 2002]
Options:
A)$ T _{1}=T _{2} $
B) $ T _{2}>T _{1} $
C) $ T _{1}>T _{2} $
D) Tension in the string always remains the same
Show Answer
Answer:
Correct Answer: C
Solution:
Tension, $ T=\frac{mv^{2}}{r}+mg\cos \theta $
For, $ \theta =30{}^\circ ,T _{1}=\frac{mv^{2}}{r}+mg\cos 30{}^\circ $
$ \theta =60{}^\circ ,T _{2}=\frac{mv^{2}}{r}+mg\cos 60{}^\circ \therefore T _{1}>T _{2} $
