Wave Mechanics Question 627
Question: The wave described by y =0.25 sin $ (10\pi x-2\pi t), $ where x and y are in meters and t in seconds, is a wave travelling along the:
Options:
A) $ -ve $ x direction with frequency 1 Hz.
B) $ +ve $ x direction with frequency n Hz and wavelength $ \lambda =0.2m $ .
C) $ +ve $ x direction with frequency 1 Hz and wavelength $ \lambda =0.2m $
D) $ -ve $ x direction with amplitude 0.25 m and wavelength $ \lambda =0.2m $
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Answer:
Correct Answer: C
Solution:
[c] $ y=0.25,\sin (10\pi x-2\pi t) $ Comparing this equation with the standard wave equation $ y=a,\sin (kx-\omega t) $ We get. $ k=10\pi \Rightarrow \frac{2\pi }{\lambda }=10\pi \Rightarrow \lambda =0.2m $ And $ \omega =2\pi ,or,2\pi v=2\pi \Rightarrow v=1Hz $ The sign inside the bracket is negative, hence the wave travels in + ve x- direction.
BETA
