Extreme f.o.c or heavy arrow

[enewman]

Does momentum mean anything for what we do, ABSOLUTELY? Where does momentum come into play? When a big bone is hit.

Why does momentum matter when the bone is hit? When bone is hit, we are going to have a big change in velocity. Now we look at impulse. What is impulse? The change in momentum. Now impulse needs to be short; the longer the impulse is, the less chance of a bone breach. This is where mass comes into play. Remember inertia. The more mass, the more inertia, the less impulse time, the easier it to breach bone.

[enewman]

To put all of this together.

KE is what gives us the ability to penetrate. Momentum is what makes the arrow hard to stop or change direction.

When people say KE means nothing in archery, You now know that is a false statement.

[enewman]

Here is an efficiency test on a bow tech reckoning 35. you can see as weight is added, we see an increase in efficiency. If you look at the 70lb section you will see that the efficiency started to Plato at 500gr. and then doesn't really increase till 700gr. What does that mean. It means for that bow and as long as you are not hitting a big bone and if you were to match KE at the target then you are not going to see a difference between a 500gr vs a 600gr arrow. Now, this is where trajectory comes into play. If the trajectory is too much for you with the 600gr then the 500gr will be a better choice for you. You just have to stay off of the big bone.

[c3products20]

Now to the confusion.

Let's look at physics only. Physics states that two objects of equal momentum but unequal mass. The object with the highest KE will be harder to stop.

The heavy arrow people say (Ashby followers) That momentum built on mass will outperform momentum built on velocity. If this was a true statement, then physics is wrong.

Now, this brings me to the test I asked the question to.

arrow 1 at 400gr and .520 momentum vs arrow 2 at 600gr .520 momentum. If you test this in a constant medium, you will see that the 400gr will out penetrate the 600gr. (not talking hunting) Physics already tells us this.

Now I said earlier; the heavy arrow will always out penetrate. So why am I saying now it won't.

This is where kinetic energy comes into play. ( now, someone above stated this cant happen from the same bow, this is 100% correct, but we are looking at physics. We do not care how we get to these velocities.)

The 400gr at .520 momentum will have a velocity of 292fps and a KE of 75.
the 600gr at .520 momentum will have a velocity of 195fps and a KE of 50. That is a difference of 50%.

To shoot those two arrows into a medium with equal retarding force, the 400gr will out penetrate the 600gr. That is physics. Back to inertia, With that much difference in KE, the 600gr arrow will not have enough inertia to overcome the 400gr with a 50% difference in KE.

Why did I want to point this out? Because in the archery world, they are teaching that momentum is what causes penetration. It's not. If momentum was, what gives us the capacity to penetrate, then with matching momentum at target, the 600gr should out penetrate.

This makes no sense... Who would, intentionally, shoot a bow 100 fps slower? It's not practical. I'm going to be shooting a 600gr arrow arrow at 285fps and it will blow through stuff the 400gr arrow would bounce off of at 292 fps.

[enewman]

Here is the data from Joel Maxfield matching momentum at target (20 yards)

[enewman]

This makes no sense... Who would, intentionally, shoot a bow 100 fps slower? It's not practical. I'm going to be shooting a 600gr arrow arrow at 285fps and it will blow through stuff the 400gr arrow would bounce off of at 292 fps.

More confusion. I'm showing physics. It is not for everyone.

No one would on purpose. Yes, from the numbers you just listed, the 600gr at 285fps has 108ke. The 400gr at 292 has 75ke. That's a difference of 44%. Hell yes, that 600gr is going to smash that 400gr arrow for penetration.

[c3products20]

More confusion. I'm showing physics. It is not for everyone.

No one would on purpose. Yes, from the numbers you just listed, the 600gr at 285fps has 108ke. The 400gr at 292 has 75ke. That's a difference of 44%. Hell yes, that 600gr is going to smash that 400gr arrow for penetration.

Why are we intentionally slowing velocity to match momentum? In the real world, no one would ever do that? We would shoot a heavier arrow with more momentum and more energy. Just in case we hit a bone. Then we wouldn't have to worry about it.....

[enewman]

Why are we intentionally slowing velocity to match momentum? In the real world, no one would ever do that? We would shoot a heavier arrow with more momentum and more energy. Just in case we hit a bone. Then we wouldn't have to worry about it.....

To show what physics already tells us. That momentum is not what causes penetration. Its KE.

The test is to physically show that it is KE that gives us the capacity to penetrate. It's a test about physics.

I do not know how to explain it any different. Like I have stated lots of times. When we are shooting the same bow, how do we increase penetration if all other factors are equal. You add MASS. Why does adding mass increase penetration when shooting from the same bow. We have an increase in KE and inertia.

So for people that do not care for the physics of archery, you only need to look at MASS. Then nothing else matters.

[c3products20]

To show what physics already tells us. That momentum is not what causes penetration. Its KE.

The test is to physically show that it is KE that gives us the capacity to penetrate. It's a test about physics.

I do not know how to explain it any different. Like I have stated lots of times. When we are shooting the same bow, how do we increase penetration if all other factors are equal. You add MASS. Why does adding mass increase penetration when shooting from the same bow. We have an increase in KE and inertia.

So for people that do not care for the physics of archery, you only need to look at MASS. Then nothing else matters.

Velocity is a function of momentum. So you can't say that KE is higher on a 400gr arrow vs a 600gr arrow out of the same bow. Because the same bow isn't going to shoot a 400gr arrow 104fps faster than a 600gr arrow. Your test just doesn't make any sense from a practical stand point.. I don't know the exact numbers so bare with me. Compare a 2000 gr arrow at 40 fps you will get the same KE as a 400gr arrow at 295fps. But you will never hit an animal to find out! Also when determining KE, velocity is exponential. Momentum uses velocity linearly. So by your definition you would NEVER be able to get more KE out of the same bow by shooting a 400gr arrow vs a 600gr arrow. The same bow will not shoot a 400gr arrow 104fps faster than a 600gr arrow. Won't happen

[enewman]

Velocity is a function of momentum. So you can't say that KE is higher on a 400gr arrow vs a 600gr arrow out of the same bow. Because the same bow isn't going to shoot a 400gr arrow 104fps faster than a 600gr arrow. Your test just doesn't make any sense from a practical stand point.. I don't know the exact numbers so bare with me. Compare a 2000 gr arrow at 40 fps you will get the same KE as a 400gr arrow at 295fps. But you will never hit an animal to find out! Also when determining KE, velocity is exponential. Momentum uses velocity linearly. So by your definition you would NEVER be able to get more KE out of the same bow by shooting a 400gr arrow vs a 600gr arrow. The same bow will not shoot a 400gr arrow 104fps faster than a 600gr arrow. Won't happen

alright, back at it. first its a PHYSICS TEST. its to show physics. not about hunting. now since you don't understand lets forget the physics test. lets for get all of it.

lets look at one bow and two arrows. I don't not care what the velocity. the ke , or the momentum is. all I need to know is what the two arrows I'm looking at weigh. I have a 400gr and a 600gr. As long as I shoot the same broadhead I know that the 600gr will out penetrate the 400gr. done No more information is needed.

[enewman]

Velocity is a function of momentum. So you can't say that KE is higher on a 400gr arrow vs a 600gr arrow out of the same bow. Because the same bow isn't going to shoot a 400gr arrow 104fps faster than a 600gr arrow. Your test just doesn't make any sense from a practical stand point.. I don't know the exact numbers so bare with me. Compare a 2000 gr arrow at 40 fps you will get the same KE as a 400gr arrow at 295fps. But you will never hit an animal to find out! Also when determining KE, velocity is exponential. Momentum uses velocity linearly. So by your definition you would NEVER be able to get more KE out of the same bow by shooting a 400gr arrow vs a 600gr arrow. The same bow will not shoot a 400gr arrow 104fps faster than a 600gr arrow. Won't happen

next, what causes penetration. KE or momentum. most people over the years have decided its no longer KE its momentum. The test is to show which one it is. nothing more. once we start shooting the same bow we no longer care about KE or momentum.

I'm showing you what physics states and I showed you the test to prove it. THAT IS IT.

your confusion is you are trying to take the test that shows what causes penetration and put it into hunting. STOP. you cannot do that.

what causes penetration in the same bow and all other factors are equal. MASS.

[c3products20]

alright, back at it. first its a PHYSICS TEST. its to show physics. not about hunting. now since you don't understand lets forget the physics test. lets for get all of it.



lets look at one bow and two arrows. I don't not care what the velocity. the ke , or the momentum is. all I need to know is what the two arrows I'm looking at weigh. I have a 400gr and a 600gr. As long as I shoot the same broadhead I know that the 600gr will out penetrate the 400gr. done No more information is needed.

You could go the other way as well but it isn't practical.A 100gr arrow going 1,000 fps is going to have the same KE as the 400gr arrow going 295fps but you and I both know that isn't practical..... I'm no physicist but I believe KE is actually affected by momentum as well. Because a 600gr arrow that launched at the same speed as a 400gr arrow will have more velocity at 30 yards. Therefore the KE of the arrow is based on velocity so the momentum would actually increase the, measurement, of velocity in the heavier arrow. To a certain point.

[enewman]

You could go the other way as well but it isn't practical.A 100gr arrow going 1,000 fps is going to have the same KE as the 400gr arrow going 295fps but you and I both know that isn't practical..... I'm no physicist but I believe KE is actually affected by momentum as well. Because a 600gr arrow that launched at the same speed as a 400gr arrow will have more velocity at 30 yards. Therefore the KE of the arrow is based on velocity so the momentum would actually increase the, measurement, of velocity in the heavier arrow. To a certain point.

Yes.

by the way, a 600gr arrow at 1000fps has 1332.6 KE. I think that is a tad more than the 400gr at 292fps

KE is not affected by momentum. momentum is not affected by KE. they are both affected by mass and velocity.

[c3products20]

next, what causes penetration. KE or momentum. most people over the years have decided its no longer KE its momentum. The test is to show which one it is. nothing more. once we start shooting the same bow we no longer care about KE or momentum.



I'm showing you what physics states and I showed you the test to prove it. THAT IS IT.



your confusion is you are trying to take the test that shows what causes penetration and put it into hunting. STOP. you cannot do that.



what causes penetration in the same bow and all other factors are equal. MASS.

So your trying to prove that a lighter object traveling at a higher rate of speed will penetrate into a theoretical media farther than a heavier object traveling at a lower rate of speed? All of this would have to occur in a vacuum, I have to add, because if wind was involved your lighter object would slow way down!

[c3products20]

Yes.

So the amount of penetration is based on momentum?