[单选题]
A 1000-kg car traveling at 25 m/s runs inkq4/+ dr h8wn,nr dn-k/aqjh 5secq25 to the rear of ihk344c/nh lw .fk t.ja stopped car that has a mass of 1500 kg and they stick together. What is the speed3.jk4 i.hkth/w ncf l4 of the cars after the collision?
