The other day, I found this puzzle laying on a floor:
This holds true. Why? $$w=2u$$
There was nothing else on it. It looked like an equation of some sort, although I had no clue about the $w$ and $u$ variables. It looks somehow related to physics, maybe a magical object that always has its weight be twice its speed? Can't be sure, and it looks like I have to prove it. Prove magic? Nah. Prove something so broad without any given assumptions? Meh.
I have been staring at this equation for hours, wondering what it may represent, but to no avail; nothing came up on my mind. Eventually, I quit, so I'm posting this here. Maybe folks can figure something out, I'm literally exhausted! I'll go get some rest now, and, in the meantime, you can freely express an answer if you've figured one out, just be sure to support it with a proof.