A wave pulse is travelling on a string with a speed υ toward the position X-axis. The shape of the string at t = 0 is given by g(x) = A sin (x/a), where A and a are constants.

(A) What are the dimensions of A and a? (B) Write the equation of the wave for a general time t, if the wave speed is υ.


A. L, L


G(x) is the measure of the height of the ripple. As, sine doesn’t have any dimension; A must have dimension of length.


[A]=[L]


To give a proper value we need to input dimensionless quantities to sine wave. So,


[a]=[L]


B.


Given that wave velocity is v. So, the time period will be,



Here, . So,



Hence,





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