Spirit of Diablo
November 13th, 2008, 03:44 AM
Since most people here seem to lack physical knowledge, or any knowledge at all, I will try to explain the basics of projectile weapons here. If you think something is missing, something is wrong, or something is unclear, let me know.
Impact
The basic principle behind projectiles is impact; something impacts with an amount of energy, and it either hits the target and bounces off it, or it hits the target and penetrates in it. The difference between bouncing back or penetrating is the area over which force is applied to the target. The more you sharpen an edge, the more likely it is to penetrate. The key to damage is the energy contained in a projectile; the more energy, the higher the impact. The more energy, the deeper the penetration. Since most penetrating weapons are relatively light, their energy is mainly determined by the speed at which they travel. I’ll focus on the main purpose here (i.e. you can break somebody’s skin with a sharp rock, thus penetrating into the body. However, much more damage is done by the impact.)
Energy contained (momentum) in a projectile is determined by both mass and speed of the projectile. Impact is determined by the force (F) with which the projectile hits the target times the time it takes (Δt) to hit the target. The shape of the projectile doesn’t have anything to do with the impact, only with the probability of penetrating.
-Momentum; p = mv
(Δp = mΔv)
(Δp = vΔm) Very unlikely to occur, since mass usually doesn’t change.
-Impact; I = ∫FΔt = Δp
(∫FΔt = mΔv)
Note that mass (m) can be any value, it just can’t change in mid-air, while velocity (v) can.
Thrown weapons
With thrown weapons, the main problem is lack of accuracy, not lack of power. All the energy put into them is put there by your arm, so it’s dependent on your strength. There are two types of thrown weapon; weapons with impact, and weapons who penetrate. With the first type, you can think of basically anything you can pick up and throw with relative ease (or a so called “ill-prepared man’s weapon”); rocks, bricks, baseballs, etc. This is fairly inaccurate over a longer distance, and easy to sidestep. If they hit, however, the result will be bruising, leading up to concussion and broken bones.
The main goal of a penetrating thrown weapon is to hit something with the sharp part of the weapon. For this, you need either lots of practice or a weapon with a lot of sharp parts. You also have to pay attention to the movement of the weapon; you can throw a shuriken knife over a short distance with in a relatively straight line, but if you need to throw it far, it will fall to the ground fairly fast. Throwing stars spin, so they follow a straight trajectory for a longer distance. All over all, thrown weapons can do a fair deal of damage in the hands of a trained user, in close combat, but for longer range attacks, they are pretty much useless. If you hit somebody correctly, the result will be excessive bleeding, and it might cause some permanent damage in cutting though muscles.
p = mv, where both m and v are variable. This makes the momentum very hard to predict.
Bows and arrows
With a bow, you gain accuracy, but you lose impact. The impact is less necessary though, since arrows are mostly designed to penetrate. In a bow, energy from your arm is stored in the string, and released into the arrow. This takes out the need for you to add speed to the projectile, the bow does this for you. Shooting with a bow takes some practice, but it's fairly easy to hit a target. Correctly hitting a target will result in a penetration between 2 and 5 centimeters, depending on the type of bow used, and the tips on the arrows.
p = mv, where v is relatively constant, but dependant on a variable m, the higher m is, the lower v is.
Crossbows and bolts
This works basically the same as a regular bow, only it’s string can contain more energy, and thus it has greater impact. This means that, where an arrow will just penetrate, a crossbow bolt will rip the target open.
↑p = m↑v, where the increase in velocity (v) is directly proportional to the increase in momentum (p).
Firearms
In firearms, the energy comes from chemical substances, which detonate to propel a projectile towards a target. This has to do with the expansion of gasses and the pressure it produces, I will post a topic on this in the Pyro-section in the next week.
Impact
The basic principle behind projectiles is impact; something impacts with an amount of energy, and it either hits the target and bounces off it, or it hits the target and penetrates in it. The difference between bouncing back or penetrating is the area over which force is applied to the target. The more you sharpen an edge, the more likely it is to penetrate. The key to damage is the energy contained in a projectile; the more energy, the higher the impact. The more energy, the deeper the penetration. Since most penetrating weapons are relatively light, their energy is mainly determined by the speed at which they travel. I’ll focus on the main purpose here (i.e. you can break somebody’s skin with a sharp rock, thus penetrating into the body. However, much more damage is done by the impact.)
Energy contained (momentum) in a projectile is determined by both mass and speed of the projectile. Impact is determined by the force (F) with which the projectile hits the target times the time it takes (Δt) to hit the target. The shape of the projectile doesn’t have anything to do with the impact, only with the probability of penetrating.
-Momentum; p = mv
(Δp = mΔv)
(Δp = vΔm) Very unlikely to occur, since mass usually doesn’t change.
-Impact; I = ∫FΔt = Δp
(∫FΔt = mΔv)
Note that mass (m) can be any value, it just can’t change in mid-air, while velocity (v) can.
Thrown weapons
With thrown weapons, the main problem is lack of accuracy, not lack of power. All the energy put into them is put there by your arm, so it’s dependent on your strength. There are two types of thrown weapon; weapons with impact, and weapons who penetrate. With the first type, you can think of basically anything you can pick up and throw with relative ease (or a so called “ill-prepared man’s weapon”); rocks, bricks, baseballs, etc. This is fairly inaccurate over a longer distance, and easy to sidestep. If they hit, however, the result will be bruising, leading up to concussion and broken bones.
The main goal of a penetrating thrown weapon is to hit something with the sharp part of the weapon. For this, you need either lots of practice or a weapon with a lot of sharp parts. You also have to pay attention to the movement of the weapon; you can throw a shuriken knife over a short distance with in a relatively straight line, but if you need to throw it far, it will fall to the ground fairly fast. Throwing stars spin, so they follow a straight trajectory for a longer distance. All over all, thrown weapons can do a fair deal of damage in the hands of a trained user, in close combat, but for longer range attacks, they are pretty much useless. If you hit somebody correctly, the result will be excessive bleeding, and it might cause some permanent damage in cutting though muscles.
p = mv, where both m and v are variable. This makes the momentum very hard to predict.
Bows and arrows
With a bow, you gain accuracy, but you lose impact. The impact is less necessary though, since arrows are mostly designed to penetrate. In a bow, energy from your arm is stored in the string, and released into the arrow. This takes out the need for you to add speed to the projectile, the bow does this for you. Shooting with a bow takes some practice, but it's fairly easy to hit a target. Correctly hitting a target will result in a penetration between 2 and 5 centimeters, depending on the type of bow used, and the tips on the arrows.
p = mv, where v is relatively constant, but dependant on a variable m, the higher m is, the lower v is.
Crossbows and bolts
This works basically the same as a regular bow, only it’s string can contain more energy, and thus it has greater impact. This means that, where an arrow will just penetrate, a crossbow bolt will rip the target open.
↑p = m↑v, where the increase in velocity (v) is directly proportional to the increase in momentum (p).
Firearms
In firearms, the energy comes from chemical substances, which detonate to propel a projectile towards a target. This has to do with the expansion of gasses and the pressure it produces, I will post a topic on this in the Pyro-section in the next week.