What would it take for a human, like me, to accelerate oneself to 60 mph? AKA 88 feet per second?
It’s basically impossible to casually do the math unless you stick to SI units (kilograms, meters.. seconds come for free, watts are familiar enough, and joules &c are strictly logical).
What’s really nice is once you know your wattage, multiplying by time once gives you total energy for a given workout. You can imagine you’re accelerating the whole time, if only the impeller inside did any useful locomotion.
So if I row 100 W (moderate workout) for 10 seconds, I have rowed 1,000 J = 1 kJ.
Now, e = ½mv2, where m = about 100 kg total, myself and the erg. 80 to 100 kg.
The v is in meters / second, which is 27 at 60 mph, so let’s just say 30.. 10 is about 20 mph.
So ½m becomes 40 or 50, now all you have to do is square the speed. 10 is fine, so now we’re talking 40-50 * 100 = 4,000 to 5,000. Joules, total energy.
So we divide by time to get watts, and everything’s familiar.
I can row 4-5 kJ at 100 W in 40 to 50 seconds. That’s how long it would “take” to accelerate to 10 m/s (about 20 mph), assuming no losses (it’ll make noise, and heat, like a car, so we may get only half).
Doubling that would quadruple the wattage (or time, they factor equivalently). (40 mph in 2 minutes or so)
Tripling would 9-tuple it. 60 mph in 6 minutes.
So, there’s your answer. I’m not going to gauge losses, and it’s hard to estimate how much a locomotive erg would weigh (I know, bicycles.. could just use that weight but why not erg-o-motive).
It would take 5 to 6 minutes for a human like me to accelerate oneself to 60 mph, assuming no losses to heat/noise, etc.