Bad Version[]
IGNORE THIS
So this started as a joke, but I decided to do it and I learned how to do Angular scaling out of it (I think), so it all works out.
The Feat[]
Spongebob apparently runs to that mountain in back in a hilariously short timespan.
The Calculation[]
Spongebob pixels: 157
Rock pixels: 98
Screen pixels: 360
According to "Spongepedia", Spongebob is 4 inches tall.
2atan(tan(70/2)*(157/360)) = 0.00711284432 degrees
Plugging these into the angular calculator, I get a distance of 818.41 meters.
818.41 meters / 0.023 seconds = 35583.04348 m./s or Mach 104. Massively Hypersonic Quickster. I haven no idea if this is at all applicable but hey, its a thing.
ArbitraryNumbers Revision[]
Credit to ArbitraryNumbers.
The mountain should be comparable to brain coral in height. So 1.6 meters.
Using your pixel measurements and plugging these values into the angsize calculator will get you 1.9055 meters. Since Spongebob crossed this distance twice, that's 3.811 meters.
That should be 165.7 m/s, or Subsonic.