Sun May 13, 2012 By:

I could not get how to solve this question: In the given equation y=Asin(wt-kx), obtain the dimensional formula of w and k; x, y, A-distances, t - time taken

Expert Reply
Sun May 13, 2012
A is the distance
t is the time 

the term inside the brackets has to be dimensionless for the equation to be correct(because on both sides we have units of length, y and A).So dimension of wt=dimns. of kx=M^0L^0T^0

on solving we get, w=T^(-1) and k=L^(-1)

OR we know w is angular velocity which is angular displacement by time(angular displac. is dimensionless and k is

(2pi)/lambda (2pi a dimensionless constant)

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