Wavelength from frequency

The notes of a scale are played in air and then under water. You will make the program find each wavelength in air, then in water, and how many times longer the waves are in water. Then it draws both.

The idea. $\lambda = \dfrac{v}{f}$. The frequency stays the same in water, but the speed is $1500\ \text{m/s}$ instead of $340\ \text{m/s}$.

Your tasks.

1. Inside the loop, work out in_air, the wavelength in air, in metres.
2. Inside the loop, work out in_water, the wavelength in water, in metres.
3. Find ratio, how many times longer the waves are in water than in air.