Question

Suppose you are on a cruise ship and encounter foul weather; the water’s surface has high-amplitude waves. Unfortunately, you have a history of vomiting profusely when bobbing up and down at a frequency exceeding 4 up/down cycles per minute. If the speed of the waves (relative to the ship) is 27 meters per minute and the spacing between successive wave crests is 5 meters, should your cruise friends (who don’t like being covered with vomit) stay away from you?

Answer 1

The speed of the wave is

The "wavelength" of the wave is

So, the frequency of the wave is

The frequency of the wave is 5.4 up/down cycle per minute which is greater than your threshold.

Hence your friends indeed should stay away from you.