Arrow speed...

[EcoMuse]

Hi Folks

Just got in from my afternoon practice and I got to thinking...

At what point does an arrow carry max. speed? Is it the second it leaves the string, or does it take a certain distance to reach max. velocity?

Cheers

[sparra_gump]

I am probably wrong here but id figure it would be as soon as it leaves the string as when it's flying it should lose speed due to wind resistance gravity etc.

Maybe but i dunno :P

SG.

[TOWER*2007]

it would have to be when it first left the string, nothing can speed up unless its motorised or going down vertically.

[EcoMuse]

it would have to be when it first left the string, nothing can speed up unless its motorised or going down vertically.

Yeah thats what I had in mind...just had me a little mystified...

So I guess its best to get 'em close and quick! ;)

[PeterM]

When I chronograph my bows you actually get highest speed reading with unit setup 4 to 6 feet in front of the bow......

If you look and any bow speed test video there chronographs are set up the same...

So there’s your answer....

[EcoMuse]

When I chronograph my bows you actually get highest speed reading with unit setup 4 to 6 feet in front of the bow......

If you look and any bow speed test video there chronographs are set up the same...

So there’s your answer....

Interesting....I wonder if thats due to the max speed being reached at that point (thus the arrow DOES speed up after launch) or rather thats the closest to safely place the chronograph to the bow??

[Drifty]

Once the string stops pushing the arrow, it MUST slow down. If its not being pushed with greater force than the resistance of wind/gravity etc then it is slowing down.

That's as simple as it can be put.


Edit: After some more thought into this. The arrow "may" actually speed up. Thus from the energy being put into the arrow at the back, and having to travel to the front of the arrow before accleration takes place.

Since the arrow bends, this somewhat rule applies. I guess you could also say that the stiffer the arrow (higher spine) the closer to the bow it will be for its maximum speed. Hence the energy from the string would transfer forward through the arrow faster on a stiffer arrow.

[EcoMuse]

Excellent explanation Drifty

[Drifty]

I think way too much. LOL

After some more thought on this, I have come to the conclustion that an arrow will speed up after it leaves the string.

But...

An arrow will flex as its being shot. We all know this, but once the string stops pushing the arrow and the last bit of pressure is applied, the arrow should be at full flex. (in theory) The arrow will therefore auto straighten out which in turn actually pushes the tip faster than the whole arrow is travelling at. It's like running at 20kph and then pushing your arm out...

Once the arrow has flexed back straight, at that exact point is the arrow's maximum speed. Once it passes straight, it is "slowing" because in a straight line the arrow is actually shrinking in length.

Although these measurements are tiny, they do exist.

Anyway, my head hurts from thinking too much. LOL