[填空题]
A 42,000-kg spaceship is to travel to the vicinity of a star 6.0 li (,ctb2yc po-qw wm(2+ga9pq 0ycv lq2ght-years frovcl, (2 qpc2 9-oaym2qpt0 cgwb +wy(q9lf 2vczk *h2zgl/1u dm Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. How much work must be dhu k2cd92*v1zl fzgl/one on the spaceship to bring it to the speed necessary for this trip? u = c
