Laws Of Motion Question 225
Question: A man measures time period of a pendulum $ (T) $ in stationary lift. If the lift moves upward with acceleration $ \frac{g}{4}, $ then new time period will be [BHU 2001]
Options:
A) $ \frac{2T}{\sqrt{5}} $
B) $ \frac{\sqrt{5}T}{2} $
C) $ \frac{\sqrt{5}}{2T} $
D) $ \frac{2}{\sqrt{5}T} $
Show Answer
Answer:
Correct Answer: A
Solution:
$ T=2\pi \sqrt{\frac{l}{g}} $
therefore $ \frac{{{T}’}}{T}=\sqrt{\frac{g}{{{g}’}}}=\sqrt{\frac{g}{g+\frac{g}{4}}}=\sqrt{\frac{4}{5}}=\frac{2}{\sqrt{5}} $
