# If the frequency of a wave is 2.0 cycles per second and its speed is 0.04 meter per second,what is the wavelength of the wave?

$\frac{0.04 \frac{m}{s}}{2.0 {s}^{- 1}} = 0.02 m$
To solve this problem, start with the fact that the desired answer (wavelength) has units of meters ($m$). Therefore, you will want the wave speed ($004 \frac{m}{s}$) in the numerator of the expression in order to get $m$ in the numerator of the answer.
The next challenge is to get $s$ out of the denominator. You can do this by dividing by the frequency ($2.0 {s}^{- 1}$), because diving by ${s}^{- 1}$ is equivalent to multiplying by $s$. In other words, a unit that lies in the denominator of the denominator is equivalent to being in the numerator.