[填空题]
A 42,000-kg spaceship is t7s nj1xmcrx 5t 08w844v oaaz7iyuy:z o ttqd5ujn2ee8th*t 2 / travel to the vicinity of a star 6.0 light-years from Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. How much work must be done on the spaceship to bringud52n j*ht te/qt2et8 it to the speed necessary for this trip? u = c
