Except cannonballs are both (usually) iron, and incredibly dense. Coconuts are neither of those things. Even moving at the same speed as a cannonball, they would not have the same energy because they have less mass. All in all, 10/10, crystal beats coconut.
Edit: I'd also like to know what these other glaring issues in my post were. Or at least what you think they are. The more I learn my errors the more I can improve!
Edit: I'd also like to know what these other glaring issues in my post were. Or at least what you think they are. The more I learn my errors the more I can improve!