Luckily we’ll never have to worry about that because we can’t actually accelerate anything that fast.
It’s theoretically possible that we could find some other way to travel FTL, like warp drives, or wormholes, but there is no way we can just keep our foot on the gas and get to that speed in the conventional way.
Worm holes. Worm hole drive is the only way imo. Imagine a 10 mile jump 1,000 times a second at zero actual velocity. That’s solar exploitation speed. With higher energies the worm holes/jumps can be farther distances. It just requires a large energy supply. The worm hole drive itself requires something else, beyond contemporary physics.