I don't think kinetic energy is the correct measure here.
The correct measure is momentum, which is mass times velocity.
When you split wood, you are not transferring kinetic energy to the log. Instead, you are attempting to drive the wedge through the log and the log is trying to stop you. So what's important is the value of the thing that represents the "tendency for an object to continue to move". That is momentum, not kinetic energy.
I won't get into the physics too deeply because BB will come in here and bust my stones, but I think this is really a very simple issue -
The momentum of the maul head is maul mass times velocity. If we swap weight for mass to simplify things, then it becomes apparent that you will have equal splitting power with
a 4 pound maul swung at a given speed X and an 8 pound maul swung at half the speed X.
In other words, it would only make sense to use a 4 pound maul if you could swing it twice as fast as an 8 pound maul. Most people can't.
By extension, you need to swing a 6 pound maul about 1/3 faster than an 8 pound maul to have the same splitting ability. Again, most men can't.
There is, of course, a limit to how heavy the maul can be. While it is true that an 80 pound maul could be swung at only 1/10th the speed of an 8 pound maul to achieve the same splitting effect, very few people could lift the 80 pound maul high enough and comfortably enough to generate the head speed required.
So for most men, 8 pounds is about the right balance between easy to lift to the top of the stroke and easy to accelerate to the proper velocity on the downstroke.
With women, the number is closer to 6.
OK - I lied, sorry BB, time to debunk the 1/2mv squared misunderstanding.
Think of two billiard balls exactly the same.
One is still and the other is driven into it for a direct impact. This is an "elastic collision".
Intuitively you know that if ball 1 is hit at 20 mph into ball 2, then, after the collision, ball 1 is still and ball 2 is travelling at 20 mph.
So far, every Bud drinking, Marlboro smokin physicist in the world gets it.
No lets repeat and increase the speed of Ball 1 by 10 mph to 30 mph. We look and we see that kinetic energy has increased from massx400(mph^2) to massx900(mph^2). Wow! Look at all of that kinetic energy. We really whacked that ball good - the kinetic energy more than doubled! whoop.
But what happened to Ball 2. Yes, as you might have expected, ball 2 is travelling at 30mph. Hmmm.
What this shows is that Kinetic Energy really doesn't give you a feel for what happend - Kinetic energy increased by more than double, but the speed increased only by the increase of the input speed.
