[单选题]
A car travels at 15 m/s for 10 s. It then-4j :c9 x y9nv8qgki(w-gfnjch-fb3 e speeds up with a constant acceleraa)3td 5ueb+g/ fkzcok3v 15lktiob a1fk)+zv3o / 35 ekuckt5gdln of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?
