Am I getting anything wrong here?
I think a knife uses force over a small area rather than energy, as pressure to cause cuts, splits and cracks.
A club can have the same pressure as the knife, but the club carries greater momentum and will knock around things more.
A bullet causes damage through the energy it carries and causes heat and deformations as it hits the target.
When people talk damage with bullets they use energy, but with melee it’s usually force. But when should I use them? Both are used at the same time but one is doing more of the effect. Don’t both result in work?
Like a force over a distance is work and thus the same as kinetic energy. Joules.
But if it’s pressure doing work I get unsure. I mix up how things break all the time.
In: Physics
You are on the right track. Saying a club has the same pressure as a knife isn’t quite right, as people have mentioned pressure is a factor of force over an amount of space. However that’s not necessarily inaccurate either, as that is why you can find blunt weapons with spikes and stuff attached to them.
When talking about bullets and mentioning energy, they’re generally talking about kinetic energy, which is another method for measuring how much energy a bullet has. It’s relevant because kinetic energy is equal to half an object’s mass times the square of its velocity. This means that increasing speed has way more of an effect on kinetic energy than increasing its mass, but keeping velocity steady. Increasing velocity along with using harder projectiles is what influences the ability to penetrate armor.
So bullets cause damage for the same reason knife points do. They put a relatively large amount of energy into a rather small spot. High pressure. You can actually see that from an general perspective, most bullets done carry a lot of energy compared to other things. Some bug guns do have a lot of recoil, but it’s not going to throw you off your feet. Simply speaking, any action has an equal and opposite reaction. It’s oversimplifying a bit, but any recoil you feel is basically similar to what propels the bullet out the other end, after you account for energy moving the gun and whatnot.
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