Finding the wavelength of a wave?

Question

The equation of a wave is:
[IMG]http://i27.tinypic.com/1i037l.jpg[/IMG]

Find amplitude: 3.4
Find wavelength: ?

I can't figure out how to find the wavelength. I tried using the formula 2pi/ (pi/3.4) to get 6.8, but that isn't correct.

Answer 1

Let's see. The normal equation of wave has a trig function (sin in your case) with an argument of the form



k*x -w*t



c = lambda*frequency = w/k = 0.66 m/s



f = w/2*pi = 8.25 Hz

lambda = c/f = 8 cm



In the equation you were given, you can see directly that the wave speed is 66 cm/s. You can check the answer above by noting that 8*8.25 = 66

Answer 2

Use the formula : frequency = velocity x wavelength.

Answer 3

compare with standard equation

y=Asin(kx-wt)

thus, here k=pi/4

w=66pi/4

there fore

frequency=2piw=33

velocity=w/k=66

thus use v=f*l where l is wavelength.

we get , l=v/f=2