Answer
$f=\frac{2}{\pi}$ Hz
Work Step by Step
Comparing the given equation $y=(5.0cm)sin[1.0-(4.0 s^{-1})t]$ to $(x,t)=y_m sin(kx-\omega t)$ we obtain:
$\omega t=4 s^{-1}t$
$\omega=4 s^{-1}$
We know that $\omega=2\pi f$.
This can be written as $f=\frac{\omega}{2\pi}$.
We plug in the known values to obtain:
$f=\frac{4}{2\pi}=\frac{2}{\pi}Hz$
