Answer
(a) $\lambda = 4.2~m$
(b) $f = 48~Hz$
Work Step by Step
(a) We can find the wavelength as:
$k = \frac{2\pi}{\lambda}$
$\lambda = \frac{2\pi}{k}$
$\lambda = \frac{2\pi}{1.5~rad/m}$
$\lambda = 4.2~m$
(b) We can find the frequency as:
$f = \frac{v}{\lambda}$
$f = \frac{200~m/s}{4.2~m}$
$f = 48~Hz$
