The trip lasted 9 hours and 15 minutes, he would have much strength to keep that speed constant so much so that he still said he would hurry like hell to get there, so much so that he got there faster than expected, since he quotes either could do it at noon and he did it in 9 hours, all indicating that he kept that acceleration all the way.
I believe in idealized models there is no such thing as a minimum amount of power to move something. In less idealized models there is, but I think that is rather complicated and before you know the data to calculate it that way you probably can just use KE.
Regarding the tsunami thing: I looked into that some time ago. The problem is in principle that wave energy isn't easily described by KE.
If one has the measurements the easy way to get a low end approximation would be to take the elevation of the wave above the water surface in each point and do an integral to calculate the total PE.
For a more accurate method, you might have already found this relatively easy formula for waves in deep water. Problem is that this is a wave in shallow water, which means that those don't apply. I can't find a shallow water solution.
I've been asked to make a discussion thread on some specific calculations for Bleach since they may be possible upgrades, however i've some issues with them and would appreciate it if you could give your input whenever you have free time.
Like, this calculator shows me that a 944.7 degree celsius change to liquid water of 37.2 kg gives me a value of 146.834 mJ, and this calculator shows me that the latent heat of vaporization of the same mass of water gives me 84.25 MJ.
Adding them together gives me a total value of 231.084 mJ. Is this the value we should use for water for the vaporization of a human calc?