Ok I“m kinda in a debate with somebody on a different forum. We were talking about how Legolas fired 3 arrows at once into the Mūmakil (the big elephant).
I stated that by firing 3 arrows at once, every arrow would only have about 1/3 of the power that an arrow could have had if Legolas had fired only 1 at a time.
He asked his dad

that is supposed to be a math teacher and 'knows physics' and he says I'm wrong.
Anyway, this has to do with N=m*a. There's 3 times as much weight (m), Legolas' strenght remains the same (N) so a is 1/3 of what it would have been with 1 arrow...
Less a means less speed, less speed means less damage...
But since you have 3 arrows, it makes up with the damage, so the total damage with 3 = the same as with 1.
So I'm right, he and his dad are wrong.
See the picture and tell me if I'm wrong or right please.
BTW the dude said that each arrow would have the power of a single-shot arrow.