- #1
Gil-H
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Homework Statement
Monochromatic transverse wave is propagating
in the positive x direction on a string (neither end is fixed).
The wave velocity is 12 m/s, amplitude 0.05 m, and wavelength is 0.4 m.
At t=0 and x=0 the string altitude is 0, and moving in
the positive y direction [i.e. (dy/dt)|(t=0) > 0]
Find the altitude y at x=0.25 m and t=0.15 sec.
The Attempt at a Solution
I figured that since y is 0 when x and t are 0, it must sine:
y(x,t) = Asin(kx-ωt)
I found the parameters I need:
k = (2π/λ)=(2π)/(0.4) = 5π
ω = vk = 12*5π = 60π
and I get
y(x,t) = 0.05sin(5πx-60πt)
I plug in the values x=0.25 and t=0.15 and get
y(0.25,0.15) = -0.02
But this is not the answer. Why?
What did I do wrong?