Answer to Question #139522 in Physics for Israel Robert

Question

The equation y= a sin (wt -kx) represent a plane wave traveling in a medium along the x- direction, y being the displacement.
a) if x is in metres, y is in second, what is the unit of k and w?
b) what physical quantity does w/k represent justify your answer
C) State whether the wave is traveling in the positive or negative direction

Answer 1

a)

$$[k]=m^{-1}\\ [w]=s^{-1}$$

b)

w/k represents speed:

$$\frac{[w]}{[k]}=\frac{m}{s}$$

c)  The wave is traveling in the positive direction.