Wave Mechanics Question 555

Question: Two simple harmonic motions are represented by the equations $ y _{1}=0.1\sin ( 100\pi t+\frac{\pi }{3} ) $ and $ y _{2}=0.1\cos \pi t $ . The phase difference of the velocity of particle 1 with respect to the velocity of particle 2 is

Options:

A) $ \frac{\pi }{3} $

B) $ \frac{-\pi }{6} $

C) $ \frac{\pi }{6} $

D) $ \frac{-\pi }{3} $

Show Answer

Answer:

Correct Answer: B

Solution:

[b] $ v _{1}=\frac{dy _{1}}{dt}=0.1\times 100\pi \cos ( 100\pi t+\frac{\pi }{3} ) $

$ v _{2}=\frac{dy _{2}}{dt}=-0.1\pi \sin \pi t $

$ =0.1\pi \cos ( \pi t+\frac{\pi }{2} ) $
$ \

Therefore Phase,diff.,={\phi _{1}}-{\phi _{2}}=\frac{\pi }{3}-\frac{\pi }{2}=\frac{2\pi -3\pi }{6}=\frac{\pi }{6} $