Wave Mechanics Question 622
Question: The displacement y of a particle in a medium can be expressed as, $ y={{10}^{-6}}\sin ( 100t+20x+\frac{\pi }{4} )m $ where t is in second and x in meter. The speed of the wave is
Options:
A) $ 20m/s $
B) $ 5m/s $
C) $ 2000m/s $
D) $ ~57m/s $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] From equation, $ \omega =100 $
$ \
Therefore ,\frac{2\pi }{T}=100\Rightarrow v=\frac{100}{2\pi } $
$ \frac{2\pi }{\lambda }=20\Rightarrow \lambda =\frac{2\pi }{20} $
$ v=\lambda v=\frac{2\pi }{20}\times \frac{100}{2\pi }=5m/s $
BETA
