Who said that physics wasn't fun?
04-16-2007, 03:05 PM
#322
Join Date: Jan 2007
Location:
Posts: 83
RE: Who said that physics wasn't fun?
ORIGINAL: bow_hunter44
ORIGINAL: doublelunginem
Bowhunter44, Thanks for the terminology...it's all coming back to me...lol
So the KE would have to be a parabola since it is the integral of the draw force curve or the area under the curve.
Actually the graph of KE is parabolic because it is a quadratic function (the velocity squared). The integral of the draw force curve (yes the area under the curve) represents the total potential energy stored in the bow at full draw.
Just trying to refresh here, so how would the momentum graph reach a vertex (which we both agree that it must) since it is a linear function. I guess my thoughts are leading me to the fact that in this situation of dealing with bow performance, momentum would have to be graphed in relation to KE. As I stated before, when we get to the vertex of the KE graph, we are dealing with the maximum efficiency of the bow in the test.
Where the maximum effeciency of the bow is realtive to the vertex of the parabola of the KE graph, I honestly don't know. I don't have an intuative feel foreither. Great questions! Arthur, can you help out?
Once this is fixed, velocity decreases exponentially as weight goes up. So would this mean that the graph of the momentum be a " / " with half of an upside down parabola following it and connecting at the highest point?
I doubt it - unfortuantely. I suspect if that were to happen it would be serendipitous and not out of necessity.
The 2nd half would resemble y= 1/x ? Or would it be y = -x? Dude, you ask great questions!!
What I am attepting to prove with out the math proplems or actual test results is that momentum and KE are so closely related that they would maximize at the same point. If infact, velocity is decreasing "exponetially" once the bow has maximized efficiency and KE is maximized, then momentum would have to decrease exponentially at that point as well.
Again, I doubt that is necessairly true. Instead of the decrease of momentum being a graph of P = 1/mv it could be P = -mv, simply a negative slope of the linear momentum graph (P = mv). But again, you ask good (tough to answer) questions.
P.S...I had a physics and chemistry teacher simular to you in HS....he's the one that got me so interested in this stuff. We had a lab every week and it was all real life scenerios. We would spend Monday learning the physics and the rest of the week performing the physics that we learned...Lab report was due by end of class on Friday for a grade. He never taught from a book and never helped with the Labs...you had to listen on Monday very closely and figure it out on your own. He was the BEST DAMN TEACHER I ever had!!!!
Well, I doubt I'm the best damn teacher around. But it sure is nice to hear that some of us do make a difference. Obviously your physics teacher did (make a difference) as your recall of physics is great and you analytical skills are great as well!
Bowhunter44, Thanks for the terminology...it's all coming back to me...lol
So the KE would have to be a parabola since it is the integral of the draw force curve or the area under the curve.
Actually the graph of KE is parabolic because it is a quadratic function (the velocity squared). The integral of the draw force curve (yes the area under the curve) represents the total potential energy stored in the bow at full draw.
Just trying to refresh here, so how would the momentum graph reach a vertex (which we both agree that it must) since it is a linear function. I guess my thoughts are leading me to the fact that in this situation of dealing with bow performance, momentum would have to be graphed in relation to KE. As I stated before, when we get to the vertex of the KE graph, we are dealing with the maximum efficiency of the bow in the test.
Where the maximum effeciency of the bow is realtive to the vertex of the parabola of the KE graph, I honestly don't know. I don't have an intuative feel foreither. Great questions! Arthur, can you help out?
Once this is fixed, velocity decreases exponentially as weight goes up. So would this mean that the graph of the momentum be a " / " with half of an upside down parabola following it and connecting at the highest point?
I doubt it - unfortuantely. I suspect if that were to happen it would be serendipitous and not out of necessity.
The 2nd half would resemble y= 1/x ? Or would it be y = -x? Dude, you ask great questions!!
What I am attepting to prove with out the math proplems or actual test results is that momentum and KE are so closely related that they would maximize at the same point. If infact, velocity is decreasing "exponetially" once the bow has maximized efficiency and KE is maximized, then momentum would have to decrease exponentially at that point as well.
Again, I doubt that is necessairly true. Instead of the decrease of momentum being a graph of P = 1/mv it could be P = -mv, simply a negative slope of the linear momentum graph (P = mv). But again, you ask good (tough to answer) questions.
P.S...I had a physics and chemistry teacher simular to you in HS....he's the one that got me so interested in this stuff. We had a lab every week and it was all real life scenerios. We would spend Monday learning the physics and the rest of the week performing the physics that we learned...Lab report was due by end of class on Friday for a grade. He never taught from a book and never helped with the Labs...you had to listen on Monday very closely and figure it out on your own. He was the BEST DAMN TEACHER I ever had!!!!
Well, I doubt I'm the best damn teacher around. But it sure is nice to hear that some of us do make a difference. Obviously your physics teacher did (make a difference) as your recall of physics is great and you analytical skills are great as well!
I am leaning more to the fact that the graph of momentum being a parabola also. The reason being is that the data for the graph comes directly from the results of the KE graph. We are entering values for arrow mass and velocity in both the KE and Momentum graphs. These numbers would be based on actual results. We are dealing with varibles such as the bow's maximum efficiency (which varies from bow to bow).
I guess what I am saying is that although momentum should be linear in form (y=mx + b.....x being the value for velocity), the values we enter for x will be effected my the bows level of efficiency, which brings us right back to the bows available KE. In other words, if a bow fires a 400 grain arrow at 300 fps, we generally say that if you go to a 500 grain arrow, it will shoot 270 fps. But this is not set in stone as this bow may become signicantly more efficient and shoot it at 277 fps which is what causes the KE to go up. The decrease in speed between set integrals of arrow mass increase would become less and less until the bow reaches it's "maximum efficiency" andbeyondthat point, the decrease in speed would become more and more between those same integrals of arrow mass increase.
04-16-2007, 03:23 PM
#323
Join Date: Feb 2003
Location: Blissfield MI USA
Posts: 5,293
RE: Who said that physics wasn't fun?
ORIGINAL: Straightarrow
Tfox, did you actually make it, or was it from you archery software? The reason I ask, is that I've never seen one for sale, or known anyone to shoot them. I knew they increased FOC, but I never knew by how much. In theory, they sound great, but I was always leary about the 40 lb spine range. As familiar as I am with dynamic spine and how the spine ratings on many arrows can be misleading, I wondered about these.
If they are spined correctly at 70 lbs, I'd love to try them. Unfortunately, I'd then have to find a shop that sold them. I wouldn't buy them without shooting a sample first.
Tfox, did you actually make it, or was it from you archery software? The reason I ask, is that I've never seen one for sale, or known anyone to shoot them. I knew they increased FOC, but I never knew by how much. In theory, they sound great, but I was always leary about the 40 lb spine range. As familiar as I am with dynamic spine and how the spine ratings on many arrows can be misleading, I wondered about these.
If they are spined correctly at 70 lbs, I'd love to try them. Unfortunately, I'd then have to find a shop that sold them. I wouldn't buy them without shooting a sample first.
I believe this is because the back half is tapered and the back of the arrow flexes more than the front does, unlike a regular arrow. Probably the best arrow I have used with fixed blades. If I go back to carbons this is the arrow I will use.
I want to do some experimenting with them though next time I build them. I just need to get all the component sizes right first. And get the money
.Paul
04-16-2007, 03:26 PM
#324
Fork Horn
Thread Starter
Join Date: Feb 2007
Location: Idaho
Posts: 384
RE: Who said that physics wasn't fun?
ORIGINAL: davepjr71
I never said that the Laws do not apply.I said that you are only taking 1 part of the whole. If you take only 1 part of the whole then keep thinking your narrow minded thoughts. There is much more to it than that as quicksilver and others have stated. I love the way you keep changing around what I say. Classic.
Youkeep saying about me shooting just foam. I actually used sheets of compressed partical board stacked verticaly and compressed with bolts in each corner for the test I performed. And of courseI only shot field tips because the range does not allow broadheads. The foam targets are meant to use friction to slow the arrow down as quick as possible.
By the way quicksilver says that field testing is all we have and you agree? You just said that our field testing is all crap and Ashby is all that matters.
ORIGINAL: bow_hunter44
ORIGINAL: davepjr71
You crack me up.
You crack me up.
Youkeep saying about me shooting just foam. I actually used sheets of compressed partical board stacked verticaly and compressed with bolts in each corner for the test I performed. And of courseI only shot field tips because the range does not allow broadheads. The foam targets are meant to use friction to slow the arrow down as quick as possible.
By the way quicksilver says that field testing is all we have and you agree? You just said that our field testing is all crap and Ashby is all that matters.
04-16-2007, 03:27 PM
#325
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: Arthur P
Education: That which discloses to the wise and disguises from the rest their lack of understanding.
Education: That which discloses to the wise and disguises from the rest their lack of understanding.
[ol][*]Facts, skills and ideas that have been learnt, either formally or informally [/ol]
My education about bows and arrows comes from the facts, skills, and ideas that I've learnt from 23 yrs of shooting. As well as from fellow shooters that I meet.
I guess when you really have no foot to stand on the best thing to do is try to belittle someone else by trying to make yourself feel better. It's really classic grade school antics and shows your lack of understanding of others.
04-16-2007, 03:30 PM
#326
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: Paul L Mohr
I have used these arrows and from what I could tell they are pretty forgiving of spine issues. I have shot them stiff enough that they should spine up to 100 lbs with my draw length, but I was shooting them at 50 lbs. They shot great, even out to 70 yards. I have also shot them slightly underspined and didn't have any real problems with them either.
I believe this is because the back half is tapered and the back of the arrow flexes more than the front does, unlike a regular arrow. Probably the best arrow I have used with fixed blades. If I go back to carbons this is the arrow I will use.
I want to do some experimenting with them though next time I build them. I just need to get all the component sizes right first. And get the money.
Paul
ORIGINAL: Straightarrow
Tfox, did you actually make it, or was it from you archery software? The reason I ask, is that I've never seen one for sale, or known anyone to shoot them. I knew they increased FOC, but I never knew by how much. In theory, they sound great, but I was always leary about the 40 lb spine range. As familiar as I am with dynamic spine and how the spine ratings on many arrows can be misleading, I wondered about these.
If they are spined correctly at 70 lbs, I'd love to try them. Unfortunately, I'd then have to find a shop that sold them. I wouldn't buy them without shooting a sample first.
Tfox, did you actually make it, or was it from you archery software? The reason I ask, is that I've never seen one for sale, or known anyone to shoot them. I knew they increased FOC, but I never knew by how much. In theory, they sound great, but I was always leary about the 40 lb spine range. As familiar as I am with dynamic spine and how the spine ratings on many arrows can be misleading, I wondered about these.
If they are spined correctly at 70 lbs, I'd love to try them. Unfortunately, I'd then have to find a shop that sold them. I wouldn't buy them without shooting a sample first.
I believe this is because the back half is tapered and the back of the arrow flexes more than the front does, unlike a regular arrow. Probably the best arrow I have used with fixed blades. If I go back to carbons this is the arrow I will use.
I want to do some experimenting with them though next time I build them. I just need to get all the component sizes right first. And get the money
.Paul
04-16-2007, 03:33 PM
#327
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: bow_hunter44
Dude? Say what? I assume that quicksilver meant by field testing that was shooting arrows into animals. Pardon my assumption. As for shooting arrows into compressed particle board, the next time I have a tag for compressed particle board to fill, I will be happy to utalize your data along with what ever is available.
ORIGINAL: davepjr71
I never said that the Laws do not apply.I said that you are only taking 1 part of the whole. If you take only 1 part of the whole then keep thinking your narrow minded thoughts. There is much more to it than that as quicksilver and others have stated. I love the way you keep changing around what I say. Classic.
Youkeep saying about me shooting just foam. I actually used sheets of compressed partical board stacked verticaly and compressed with bolts in each corner for the test I performed. And of courseI only shot field tips because the range does not allow broadheads. The foam targets are meant to use friction to slow the arrow down as quick as possible.
By the way quicksilver says that field testing is all we have and you agree? You just said that our field testing is all crap and Ashby is all that matters.
ORIGINAL: bow_hunter44
ORIGINAL: davepjr71
You crack me up.
You crack me up.
Youkeep saying about me shooting just foam. I actually used sheets of compressed partical board stacked verticaly and compressed with bolts in each corner for the test I performed. And of courseI only shot field tips because the range does not allow broadheads. The foam targets are meant to use friction to slow the arrow down as quick as possible.
By the way quicksilver says that field testing is all we have and you agree? You just said that our field testing is all crap and Ashby is all that matters.
When I PM'd you early on and asked if you wanted my results from the test you smuggly said you couldn't wait to see them. As soon as I posted them you instantly came up with 100 ways why thy do not count.
Classic and too funny DUDE. You definintely have to be young. unless you are from the hippie days, dude.
04-16-2007, 03:35 PM
#328
Fork Horn
Thread Starter
Join Date: Feb 2007
Location: Idaho
Posts: 384
RE: Who said that physics wasn't fun?
ORIGINAL: Paul L Mohr
I have used these arrows and from what I could tell they are pretty forgiving of spine issues. I have shot them stiff enough that they should spine up to 100 lbs with my draw length, but I was shooting them at 50 lbs. They shot great, even out to 70 yards. I have also shot them slightly underspined and didn't have any real problems with them either.
I believe this is because the back half is tapered and the back of the arrow flexes more than the front does, unlike a regular arrow. Probably the best arrow I have used with fixed blades. If I go back to carbons this is the arrow I will use.
I want to do some experimenting with them though next time I build them. I just need to get all the component sizes right first. And get the money.
Paul
ORIGINAL: Straightarrow
I believe this is because the back half is tapered and the back of the arrow flexes more than the front does, unlike a regular arrow. Probably the best arrow I have used with fixed blades. If I go back to carbons this is the arrow I will use.
I want to do some experimenting with them though next time I build them. I just need to get all the component sizes right first. And get the money
.Paul
04-16-2007, 03:55 PM
#329
Fork Horn
Thread Starter
Join Date: Feb 2007
Location: Idaho
Posts: 384
RE: Who said that physics wasn't fun?
ORIGINAL: davepjr71
Classic and too funny DUDE. You definintely have to be young. unless you are from the hippie days, dude.
ORIGINAL: bow_hunter44
ORIGINAL: davepjr71
ORIGINAL: bow_hunter44
ORIGINAL: davepjr71
Classic and too funny DUDE. You definintely have to be young. unless you are from the hippie days, dude.
04-16-2007, 04:13 PM
#330
Join Date: Feb 2003
Location: Blissfield MI USA
Posts: 5,293
RE: Who said that physics wasn't fun?
Not really expensive compared to other arrows, just hard to find. One of my local shops used to carry them, then the guy passed away. The new guy dropped them. Another shop can get them, but you have to order them.
Last I checked they were around $80 a dozen I think. That may have been fletched with feathers as well.
Check the web, I'm sure someone carries them.
Paul
Last I checked they were around $80 a dozen I think. That may have been fletched with feathers as well.
Check the web, I'm sure someone carries them.
Paul