Acrate with a mass of 60 kg glides through a space station with a speed of 2 m/s. an astronaut speeds it up by pushing on it from behind with a force of 180 n, continually pushing with this force through a distance of 7 m. the astronaut moves around to the front of the crate and slows the crate down by pushing backwards with a force of 160 n, backing up through a distance of 6 m. after these two maneuvers, what is the speed of the crate?