Physics proves you are ignorant. As long as a maul is moving it has energy, and if it was all used up by the top log then when you split one log the maul would always stop at the ground and never bury itself in the dirt. To split a clean, knot-free piece of hardwood like Ash, Maple, Beech etc. it takes X amount of energy, and if the person swinging the maul puts in 2X then it will split two logs. A video is a great idea though, I just picked a gopro up at the Salvation Army so it is in the works........
Ehh. The last thing I want to do is stir, but honestly physics are not on your side.
I would sorta of urge you not to try this, in spite of previous claims. It is ironically exactly the type of tomfoolery that gets people hurt.
That said, F=ma. Force equals mass times acceleration. So let's think about this, ignoring all sorts of things in physics that further make it unlikely.
You're going to need substantially more than twice the force to get the job done, but let's just say twice as much for the argument's sake. So what needs to be altered? Looking at the equation we immediately see that we're dealing with one constant and one variable to arrive at the required force.
The constant is mass, at 5lbs. If we were actually doing the physics we'd convert to correct units, but for this discussion knowing the mass isn't a variable is enough. So that leaves acceleration. Acceleration is measured in meters a second per second (m/s²). Let's subsequently consider that the variable is measured in distance over time squared. Is the distance of our acceleration changing? No. So what we're really talking about is time.
So the position being made is that one (gben) can swing a maul more than twice as fast as "normal" at the very barest of minimums. I doubt it, that's way more impressive than it sounds on the surface. Consider that a pro golfer is only able to swing roughly 20-30% faster than an average amateur, not anywhere near 100%+...
The only way this works is if the wood is of the type that wants to split just looking at it. A normal hardwood log the *requires* a decent swing, no freaking way. It's a specious plausibility that falls apart quickly when examined. I take up OA's flag.
Hopefully this goes away when it doesn't wind up as the first video of said trick on youtube.