# Homework Help: Wave problem

1. Sep 3, 2006

### scienceman2k9

Problem:

The equation of a certain traveling transverse wave is
y(x,t)=4.00sin(81.0(pi)t - 1.590(pi)x) where t is in seconds and x and y are in cenimeters. Find the speed of propagation, the period and the wavelength for these waves (express you answer in units of m/s)

So, I know A (amplitude) is 4.00cm....0.04m and the angular frequency is 81.0pi rad/s and k=1.590pi . To find the speed of propagation i divided angular frequency by k and got 50.94, but i don't know if that cm/s or not since the whole equation is based in cm. I can find the other values too, but I am not sure if I need to convert my answers.

2. Sep 3, 2006

### Andrew Mason

Convert distances to metres and rewrite the equation:

$$y(x,t)=4.00\sin{81.0\pi t} - (1.590\pi)(100x)$$

$k = 159\pi m^{-1}$ Speed of the wave is $\omega/k$ in $sec^{-1}/m^{-1} =\text{m/sec.}$
AM

Last edited: Sep 3, 2006
3. Sep 3, 2006

### scienceman2k9

I got:

v= 0.509 m/s (omega/k)

T= 0.0247 s (1/f = 2pi/omega)

wavlength= 0.0126 m (2pi/k)