Standing in the middle of a 20 m long pier, you notice that at any given instant there are 15 wave crests between the two ends of the pier. Estimate the minimum uncertainty in the wavelength that could be computed from this information.
ΔxΔp ≥ ħ/2
ΔEΔt ≥ ħ/2
The Attempt at a Solution
I don't really understand how to use the equation to solve the problem. I am given no info on momentum or its uncertainty, and therefore cannot get any relation between the two. Perhaps I am not using the right equations? Any guidance twoards getting the right tools/solving it would be great as there are multiple problems of his ype that I am stuck on, I am fine with doing work myself.