| Author |
Message |
David E. Farrell
Location: Evanston, IL Joined: 25 Jun 2007
Posts: 156
|
 Posted: Fri 12 Dec, 2008 9:25 pm Post subject: |
 |
|
| Gary Teuscher wrote: | One thing about the whole "spear has more mass than the dagger" thing -
IIRC my physics correctly, of course we have mass x velocity squared for force. |
this is my inner scientist/engineer speaking - but this is something I feel is worth getting right. For the further nit-pickers, I'm going to ignore relativistic and quantum effects - so neah :P
mass x velocity squared is actually 2 x kinetic energy (i.e. KE= 1/2 m v^2). This is not to be confused with force. Force is conventionally defined as mass x acceleration (i.e. F = ma, where acceleration is the rate of change of the velocity in time: a = dv/dt), though it can also be defined as the negative of the rate of change in 'Internal Energy' (think 'potential' energy) with position of the object (i.e. F = - dU/dx). And to make things really confusing, momentum is mass x velocity.
As to which is the more important factor when considering a strike, this you definitely got right:
| Gary Teuscher wrote: |
But a Spear thrust (or dagger) is a very complicated equation. |
Mostly because all the things I mentioned above are all related, and therefore all have a place when you consider the dynamics of a cut or impact. It just depends on what you are talking about.
Anywho...
| Gary Teuscher wrote: |
Here's the part where I think I'm getting it right, but I'm probably missing a few points. The "base" where mass is measured from is from the fulcrum down, though perhaps the weight furthest from the fulcrum is more imporatant than
the mass closer to the fulcrum.
Also, there are many "fulcrums" in thrusting a weapon. Feet or body mass going forward, the fulcrum of the waist, shoulder, elbow, wrist.
Now my question/thought is that the shoulder and elbow do most of the movement. Each of these has the part of the arm below the fulcrum as mass in additon to the weapon. I think elbow to wrsit is a good 5 pounds+ for most, from the shoulder would be even more.
So a thrust from the shoulder may have 8-10 pounds or more in additon to the weapon itself - making a a pound dagger say 10 pounds, a 5 pound spear 14 pounds.
If you have more velocity from a dgger thrust (not saying you will), even a slight bit more velocity, both will deliver a similar amount in Joulles.
Now I have no idea as to exaclty how to do the calcualtion, I leave this for those with more of a physics inclination. But it would have some effect, but only doing the calculations would truly gove the right number.
That being said, anyone know what a spear/dagger thrust would be in feet per second?
There is also the "recoil", or perhaps more accurately arm give, i.e. your wrist bends somewhat upon impact, your hide slides up the shaft a tad, etc. etc.
Adding to all that, it seems true what I call "daggers" were very well designed for the thrust, perhaps better than most spears, though it does seem the spears had a broader head to cause more disruption of tissue upon penetration, though this is of course two different aspects, penetrating armour and damage upon penetration.
My overall guess is the dagger will have similar penetrating ability to the spear used with one hand, though probably a bit less. The spear though will generally cause more damage, the dagger's damage will dpend more upon what organs are struck including arteries/veins. |
So mass is mass. If something weighs more (and is measured at a location on earth such that the acceleration due to gravity is the same) - it has more mass. Mass distribution, on the other hand - that will change when you add mass, and becomes important in things like rotational motion or bending.
In general, I think your conclusion that a (reasonably weighted) spear in one hand would have a similar penetrating ability to a dagger in one hand does make sense - but I think the reason has a lot more to do with the supporting structure for the weapon (the body of the wielder) than the mechanics of the weapon/target impact. Similarly, I would suspect that the structure of the 2-handed spear wielder could allow for greater penetration, since one would have a better 'support' for the weapon.
That said, of the demonstrations I have seen - they both do a sufficiently good job for their intended tasks. So, IMO, the question of which is better is either moot or purely academic depending on how cynical you want to be 
AKA: 'Sparky' (so I don't need to explain later  )
For he today that sheds his blood with me shall be my brother
-- King Henry, Henry V, William Shakespeare
Before I came here I was confused about this subject. Having listened to your lecture I am still confused... but on a higher level.
-- Enrico Fermi
Last edited by David E. Farrell on Fri 12 Dec, 2008 9:30 pm; edited 1 time in total
|
|
  |
 |
David E. Farrell
Location: Evanston, IL Joined: 25 Jun 2007
Posts: 156
|
| Posted: Fri 12 Dec, 2008 9:28 pm Post subject: |
|
|
| Christian Henry Tobler wrote: | Hi Gary,
Heh, yeah, except it's over a *lot* quicker. If you don't escape a ground hold immediately, you've been stabbed a lot of times. And, while one can toughen up to take a punch, the same doesn't work against a dagger point going into one's mid-brain.
Such encounters must've been truly terrifying.
All the best,
Christian |
Seriously - after your armoured combat class out here, I have learned about a whole new level of helplessness and terror.
To know that once you've been sucessfully grappled that no amount of harness will save you from your dagger wielding opponent is truly an equalizing feeling to the initial impervious feeling you get in harness.
AKA: 'Sparky' (so I don't need to explain later )
For he today that sheds his blood with me shall be my brother
-- King Henry, Henry V, William Shakespeare
Before I came here I was confused about this subject. Having listened to your lecture I am still confused... but on a higher level.
-- Enrico Fermi
|
|
|
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
All contents © Copyright 2003-2024 myArmoury.com — All rights reserved
Discussion forums powered by phpBB © The phpBB Group
Switch to the Basic Low-bandwidth Version of the forum
|
This is a standard topic