Kinematics Question 542
Question: The string of pendulum of length $ l $ it’s d it’splaced through $ 90^{o} $ from the vertical and released. Then the minimum strength of the string in order to withstand the tension, as the pendulum passes through the mean position it’s[MP PMT 1986]
Options:
A) $ mg $
B)$ 3mg $
C) $ 5mg $
D) $ 6mg $
Show Answer
Answer:
Correct Answer: B
Solution:
$ T=mg+\frac{mv^{2}}{l} $
$ =mg+2mg=3mg $ where $ v=\sqrt{2gl} $ from $ \frac{1}{2}mv^{2}=mgl $
