In the system of magic that I am using I try to follow the laws of physics as much as possible. The idea being that whatever magic can do, a scientist and machine can eventually do. One of the things my spellcasters can do is transfer and convert kinetic energy. I know there isn’t a scientific principle that allows instantaneously converting kinetic energy into heat but hey, it IS magic.
One of the fundamental rules of my magic is that it is impossible to manipulate any energy or atoms that are within 3-6 inches of a living person. The caster can't touch that space, but if they do something to the surroundings it can go into the space, ie, one can't push a rock while it is inside the field but can throw it into it. I don’t like mind control and that was the easiest fix. But it leads to an interesting complication which leads to my question.
What would happen if a midsized sedan style car going say 60 mph had all of its kinetic energy stolen? Assume the time frame for this is about 1/1000th of a second (I do not know how fast this happens changes things, I want it close to instantaneous but not quite so that another caster can maybe interfere). Also assume that all the energy (minus the heat loss, since even in magic no transfer of energy is perfect) is completely transferred into the ground in that time frame.
Now how does that change when there is someone in the car? The person means that there is a small but noticeable part of the car whose kinetic energy cannot be touched by the caster at all.
Finally how much different would this be if rather than a big heavy car going fast, it was a light small bicycle going slow? The human's protection is much more of a bicycle’s total space.
Hard science with math being given would be beneficial but I’m not looking for how many joules or whatever the unit is will be applied to each atom of the person or whatever. Mostly I want to know how this compares to a normal car accident and in general terms what effects weight and speed and proportion of vehicle protected by a living person might have when all the kinetic energy is removed like this.
The situation described is like a car hitting a wall that doesn’t break, except that it's all of the energy from every spot leaving the car at once. I know in a crash, the impact point hits first and the back end follows fractionally later, hitting what already stopped. Seems like if all the energy was stolen at once, the car would come to a complete stop and remain intact because every part stops at once. The person inside though would still keep going, essentially crashing without airbags or crumple zones or most of a car's safety features. Instead of saving the driver, the caster killed them more horribly than the accident would have. With a bike, seems like it would be the same as hitting a curb dead on, and the thing would flip (the front tire being one of the few parts that isn’t protected).
I believe this is different from any other question because of the complication of the human's null field. If not, a link to some other question will be a good answer.
Edit to clarify
This is different from a head-on crash against an immovable wall because:
- the null field inside generated by the person
- the kinetic energy is stolen from every atom of the car at once, rather than when a car hits a wall and the impact point losing the kinetic energy before the points further away from the point of impact.
Second edit; I did not understand that kinetic energy was relative to a frame of reference so when I say all the kinetic energy is taken, I mean relative to the spell caster standing on the street. Its bad enough the spell intended to save a life, stopping a runaway car, brutally kills the driver without sending them into orbit after cooking them with atmospheric friction.
This is where my mental hang-up comes from.