Aren't you describing with different words the impact with a projectile?

@L.Dutch-ReinstateMonica Somewhat, yes. Mostly in regards to the deceleration.

Unless it's free (General Products Hull?) or legally mandated, it's difficult to see why someone would design a craft that can viably survive an unintended human-killing deceleration from an unintended direction; You don't see many consumer cars designed to be drivable after you've dropped them off a skyscraper.

@notovny indeed, this is why I am interested to know if this sort of weapon may be effective.

Boy oh boy. I can heartily recommend The Expanse series (Specifically Abaddon’s Gate). There are some pretty vivid descriptions of what hard acceleration can do, especially if a bit of handwavium is applied to allow for extreme acceleration events...

@JoeBloggs cool! I believe I may have heard of that book, I will give it a shot when I can. Thanks :)

@Martijn a car going at 15km/s? I'd wait for them to hit a speed bump, I reckon. That said, maybe the car-speed bump way is a good analogy for this question.

A car going 100 km/h. Try to stop that. What do you need? Counter momentum or enough mass to stop the car

@Martijn in this case it's more like a car going 200 km/h, and we don't much care about stopping the car at all, just inducing enough G's to incapacitate the passengers. If a car goes across a speed bump at 200km/h, this is the analogy. It's more than fatal enough, although the car won't immediately stop, spinal/neck damage is impossible to avoid.

@Martijn also, due to the conservation of momentum, the faster the object is going, the less mass we actually need to do fatal damage due to acceleration (Because no matter how fast or big the ship goes, humans remain very fragile)

@Mark Not sure I understand your comment, what aspect of this do you want to relate to the question? The sudden deceleration?

@JoeBloggs - the TV show from the books has a rather splashy example of the same scene, as the young pilot discovers the Gateway's 'speed limit' for the first [& in his case, last] time. Essentially the Ring stops the ship unharmed, but doesn't take account of its inhabitant, who is next seen ermm… decorating the front of the cabin.

@Tetsujin: I was thinking more of the description of the crewman unfortunate enough to be standing in a doorway when their ship... stopped...

FYI it's a bad idea if the speed bump can be detected from a distance

@JoeBloggs - ah, yes, sorry, I was firmly fixed on the solo 'joy-rider' in his speed yacht thingy - first through the ring. Same principle, "magic handwavium stoppiness" of machine but not crew.

@RobWatts interesting, using the thruster to burn up the speed trap. It's a bit out of the frames of this question, since we assume they will hit it without decelerating, but I reckon the speed bump would have to be coated with or made out of difficult to detect materials.

I'm not sure this can be answered under "science-based". Any realistic spacecraft would disintegrate upon hitting a material "speed bump".

@Alexander it's just that we want an answer somewhat grounded in physics. Otherwise we could just use a momentum canceler to cancel out the change in momentum and handwave the whole thing. Definition of Science-Based: 'For questions that require answers based on hard science, not magic or pseudo-science, but do not require scientific citations'.

@Enthus3d then we need to spell out the limits of "somewhat". Some people had mentioned "General Products hulls". In your setting, do we have indestructible hulls, but lack momentum cancelers?

@Alexander I have actually been thinking about the same problem, your comment does make a lot of sense. I will need to do some calculations on the actual kinetic energy of some materials (eg. grains of sand), but I think you are right in that any of our current spaceships would be obliterated by most collisions at these scales

@Alexander do you think I should add a sci-fi tag and specify some theoretical hull thicknesses/durabilities?

Ran some calculations, seems like a clump of sand moving at 15,000 m/s has enough kinetic energy to penetrate roughly 87 meters of Steel Plate Armor (Head On). I will set a new tag for sci-fi, but I don't believe we'll need anything close to a General Products hull,

just better and thicker plate armors in general, in fact, most composite armors have 3-4 times the strength of steel, and nanotubes possess 600 times the strength