Answer
$v=2.65m/s$, $f=0.59Hz$
Work Step by Step
To find the velocity of the wave, substitute the known values of $g=9.8m/s^2$ and $\lambda=4.5m$ to get a velocity of $$v=\sqrt{(9.8m/s^2)(4.5m)/2\pi}=2.65m/s$$ To find the frequency, use the equation $$v=f\lambda $$ to solve for frequency $f$. $$f=\frac{v}{\lambda}$$ Substitute known values of $v=2.65m/s$ and $\lambda=4.5m$ yields a frequency of $$f=\frac{2.65m/s}{4.5m}=0.59Hz$$
