Arrow speed, what do you guys think

[TrevorM]

So I sort of started a discussion about arrow speed, and the fastest point when shooting. I said I believed an arrow would be going fastest at the moment it leaves the string. Someone else (who's fairly knowledgeable) stated that it would be at a point after that. He didn't really state why he thought that was the case. So I figured I'd see what you guys thought about it and maybe start an argument discussion here too 

[DC]

When it leaves the string. After that there is nothing pushing it and it starts to slow down.

[EdwardS]

After it stops fishtailing off the string.  Otherwise it's fanning the feathers from side to side catching air.

[aaron]

fastest at the moment it leaves the string. After that it cannot accelerate (except perhaps due to gravity or high winds).

[mullet]

I say it's fastest as soon as it straightens from paradox

[TrevorM]

I had considered Paradox, but I'd only thought of it like a spring which would only increase speed if it had something to push against. I guess the fanning action could cause some thrust, although I'm not sure it'd be enough to overcome the drag and actually increase the speed. 

[PEARL DRUMS]

Off the string. Unless you are shooting downhill.

[Urufu_Shinjiro]

I can see where one might think that some sort of momentum or acceleration would carry the arrow to a higher speed after it's left the bow but this is just a misunderstanding of physics. Once the string is no longer acting on the arrow the speed is at the maximum it's going to be, the only forces acting on the arrow at that point are gravity and wind drag. Same with a baseball, the instant the ball leaves the pitches fingers it's going the fastest it will go, which is kind of impressive if you think about it because a ball clocked at 90mph would mean that at the moment of release the pitchers hand was moving faster than 90mph.

[PEARL DRUMS]

And exactly why arrow speed is measured right off the bow when shot through a chronograph.

[steve b.]

Kinda like sprinters.  "they" say that the fastest man in the world can only accelerate for about 10 yds., afterward he is slowing.  So when you watch a sprint race you are not seeing one guy accelerating faster than the others; you are seeing one guy decelerating less than the others.  With an arrow, a bullet, whatever projectile, it slows immediately unless it is powered.

[Zuma]

This is why I always rotate my arms while releasing.
Zuma

[TrevorM]

This is why I always rotate my arms while releasing.
Zuma

You should blow on the fletchings too so it's got a good tail wind   

[loon]

fastest at the moment it leaves the string. After that it cannot accelerate (except perhaps due to gravity or high winds).

This. It'll hit better when it's going straighter, but won't be faster..


it's physics