welts

[TheJester]

Sorry if this is the wrong forum, but i want a straight answer. I know this must have something to do with the phisics on how the ball is moved, however it also may have to do more with biology. now for the question, we've all gotten welts when we've played, now how come the center of the hit is always white, surrounded by a red ring? also, if it's not a direct hit (eg side of the wriste) the white "center" goes in the same direction of the ball, making more of a oval center again surrounded by a red ring. what's causes the different colors in skin.

[synreal]

http://www.automags.org/forums/showthread.php?s=&threadid=19058&highlight=welt

from tom:
Excellent observation, good question, a little more complicated answer.

The front part of the ball hits you and starts to deform. As it flattens out against your skin (you can see this by pushing it into a table with your thumb) eventually it creates a very tight radius at the edge of the flattened part. At this point of high radius the shell fractures and you now have a paintball full of paint that is acting as a cookie cutter and giving you a ring welt.

Our plastic paintballs are much stiffer but flex very little so they don't flex enough to cause the "ring" in the welt. They just shatter like a potato chip and cause less bruising.

AGD

[Trench]

Synreal is completly correct...

Hey, why dont you explain why they hurt worse if they dont bust on you? (I know it is kind of in your above post, but ya know)

[pb-afroman]

I learned that one in ninth grade physics :) It is something called the bouncing effect. When the ball breaks on you there is only the force of it going toward you. When it bounces off there is the force of it going toward you and also the force of it leaving you. In essence this means there is just a greater ammount of force on you, so it hurts more.

[bjjb99]

When a paintball breaks on impact, much of its energy is dissipated during the process of fracturing the shell and distributing the fill. Once the shell has broken, you have a liquid (the fill) delivering any remaining impact energy to your skin.

When a paintball bounces, the ball's energy is completely delivered to you, and the object delivering the energy can be treated as a mildly deformable solid. You get a larger dose of kinetic energy, and thus it hurts more.

The whole process is similar to comparing a bullet that deforms on impact, delivering all of its energy to the target, versus a bullet which just drills right through the target, taking much of its energy with it. The deforming bullet is likely to do more damage.

BJJB