Wave Mechanics Question 577
Question: A body is executing S.H.M. When its displacement from the mean position are 4 cm and 5 cm, it has velocities $ 10cm,{{s}^{-1}} $ and $ 8,cm,{{s}^{-1}} $ respectively. Its periodic time is
Options:
A) $ \pi /2,s $
B) $ \pi s $
C) $ 3\pi /2s $
D) $ 2\pi s $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Using $ v^{2}={{\omega }^{2}}(a^{2}-y^{2}) $ we have $ 10^{2}={{\omega }^{2}}(a^{2}-4^{2}) $ and $ 8^{2}={{\omega }^{2}}(a^{2}-5^{2}); $ so $ 10^{2}-8^{2}={{\omega }^{2}}(5^{2}-4^{2})=(3{{\omega }^{2}}),or,6=3\omega $ or $ \omega =2,or,T=2\pi /\omega =2\pi /2=\pi s. $
BETA
