No accounting for particles yet, which you'll also keep hitting, making your ship's materials radioactive and causing lots of secondary particle showers, bremsstrahlung and the likes.
First the particles will act like radiation, then they'll start causing matter-antimatter pair creation with your hull, then you'll get some exotic heavy quarks popping into existence, then you'll get some Higgs particles forming and at some point questions like "what is the mass of my ship" stop making sense.
