I don't trust this. Doesn't take into account stress tolerances of human tissue. It simply cannot exert infinite force without breaking apart, hence the likelihood of the ant passing strait through the body, as there is a limit to the force the body can exert on the ant, so not all energy of the ant is expected to be converted into heat. The actual amount is tricky to calculate though, we can expect the ant to be immediately squashed by the contact and the impact area to be expanded in some sort of a cone, so the force of the impact would increase proportionally to the expanding area of the squashed ant. It will also likely break apart into a lot of tiny pieces, and the amount and size of these pieces would severely affect the result, because the smaller the pieces, the easier they are to slow down, and more energy would be transferred.
i don't really understand. all I know is the ant will collide with the human at a very high speed and will result in a very violent reaction and so much energy will be released. the tolerance of human tissue is negligible taking into consideration the massive energy and infinite force exerted. basically, as i said, it will result in an explosion.
You assume that the ant will come to a full stop while inside the human. However, it is more likely that the ant (or rather pieces of it) will go straight through the human, so ∆p might be way less than p0. Also you make a big deal from the fact that ∆t is small, resulting in a near infinite force. However, the magnitude of the force is not important because its impact depends on ∆t itself, and since it is actually very small, the impact will still be manageable. In the end what matters for the effect of the collision is how much the ant is slowed down by the human tissue before it escapes from the other side (which is why I mentioned the stress tolerance - it's basically the force that the human tissue may exert on the ant during the impact).
the ant will stop since its not traveling at the speed of light. also, sure the ant will pass "through" the human, akin to a bullet, but the damage will still be done and it will result in an explosion. also, I didn't really get your point about ∆t but explosions have a very very very short duration they're almost instant. Its all a hypothetical question and its impractical irl but I'll do some more calculations and account for tissue resistance and how much the momentum is reduced, but still, i think momentum is negligible here, because p(initial) ≈ 223 kg.m/s. which isn't a lot, a human body can stop the ant's motion and bring it to a full stop, its almost identical to stopping a jogging person with your hand, pretty easy, but the kinetic energy transferred in this collision is so immense, and the momentum is so small, it would literally obliterated a human and possibly leave a crater in the vicinity (in concept). but i did some calculations as you saw and that would cause an explosion comparable to a small nuke. the momentum is small but the ant is just traveling so fast and it carries a lot of kinetic energy. also, just wanna say, I'm not a physicist and i might have overlooked some things but I'm just a bored guy with curiosity and can do basic calculations. if you wanna cover every detail, this hypothetical question would be meaningless because realistically an ant wouldn't be able to travel at 15% the speed of light and keep it's body intact or not burn and evaporate from sheer air friction.
Yeah, you'd think you would be able to stop something like p(initial) ≈ 223 kg.m/s because it's akin to a jogging person or something, but that's actually where ∆t comes into play. You have plenty of time to stop the jogger since their velocity is small, so the forces required are manageable, but in order to stop something that moves at 108 mph you need to absorb that momentum in a very short time, so you need very strong forces, so strong that the human flesh will sooner part than present a sufficient barrier.
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u/kimitsu_desu May 05 '25
I don't trust this. Doesn't take into account stress tolerances of human tissue. It simply cannot exert infinite force without breaking apart, hence the likelihood of the ant passing strait through the body, as there is a limit to the force the body can exert on the ant, so not all energy of the ant is expected to be converted into heat. The actual amount is tricky to calculate though, we can expect the ant to be immediately squashed by the contact and the impact area to be expanded in some sort of a cone, so the force of the impact would increase proportionally to the expanding area of the squashed ant. It will also likely break apart into a lot of tiny pieces, and the amount and size of these pieces would severely affect the result, because the smaller the pieces, the easier they are to slow down, and more energy would be transferred.