A small spacecraft mass, including the crew, is 1,5x10^3 kg moves in outer space where there is no gravitational field. If the astronaut to light a laser beam of 10kW, which can reach speeds after a day due to the momentum carried by the beam?

i do not know if time will play a role here.
i mean 0(initial momentum)=U/c - mv
so v=U/mc??

The answer is 1,9 mm/s

well, my formula is giving 1.92 mm/s which is very close to the answer.
10* E3 *24*60*60/(1.5*E3*3*E8) *1000 mm/s

Yes. Thank you