1.

A transverse harmonic wave on a string is described by y(x,t) =5.0 sin(48t + 0.0264 x + pi/6),where x and y are in cm and t in sec. The positive direction of x is from left to right. (a) What are its amplitude and frequency? (b) What is the least distance between two success in crests in the wave?

Answer»

SOLUTION :Here,
y(X,t) = `5.0 sin(48t + 0.0264x + pi/6)`
The general EQUATION of a plane progressive wave is,
`v(x,t) = a sin[((2pi)/lambda(vt +x) + phi)]`
It is OBSERVED that the given equation represent a travellig waveform right to left.
Velocity, `V=48/0.0264 = 1818.18 cm s^(-1), r=5` cm.
(a) Amplitude and frequency:
Amplitude,
`(2pi)/lambda = 0.0264`
or `lambda = (2pi)/0.0264 cm = (2 xx 3.14)/(0.264) = 6.28/0.0264 = 237.8` cm
frequency,
From the equation
`v= lambda v`
`v= v/lambda =(1818.18)/(2pi) xx 0.0264 =(1818.18)/(2 xx 3.14) xx 0.0264`
`=(1818.18)/(6.28) xx 0.0264 = 289.51 xx 0.0264 = 7.64` Hz
(b) To find least distance between two successive crests in the wave.
`lambda =(2pi)/(0.0264) =(2 xx 3.14)/(0.0264) = 6.28/0.0264`
=237.8 cm= 2.38 m
(C ) When `x = lambda/4`
`phi =(2pi)/lambda xx lambda/4 = pi/2` rad.


Discussion

No Comment Found