Quote Originally Posted by The Grand Wazoo View Post
Think about a seesaw.
Put a fat kid and a skinny kid on it. The fat kid near the middle and the skinny one near the other end. This gives the skinny kid greater downward inertia.
Now move him in to the same relative distance as the fat kid. The fat kid now has greater downward inertia.

Now move him back a bit and they balance, so they have the same downward inertia (in this case, zero)
Hey that's my variable effective arm mass analogy! You mean I forgot to copywright it? Bugger!