Kinematics Question 798
Question: A mass is supported on a frictionless horizontal surface. is attached to a string and rotates about a fixed centre at an angular velocity $ {\omega _{0}} $ . If the length of the string and angular velocity are doubled, the tension in the string which was initially $ T _{0} $ it’s now [AIIMS 1985]
Options:
A) $ T _{0} $
B) $ T _{0}/2 $
C) $ 4T _{0} $
D) $ 8T _{0} $
Show Answer
Answer:
Correct Answer: D
Solution:
Tension in the string $ T _{0}=mR\omega _{0}^{2} $
In the second case$ T=m(2R)(4\omega _{0}^{2})=8mR\omega _{0}^{2} $
$ =8T _{0} $
