In a lab experiment, a 1.5-kg cart traveling at 4.3 m/s in the +x direction collides with a 2.5-kg cart traveling at 2.7 m/s in the -x direction. After the collision, you find that the 2.5-kg cart is traveling at 1.9 m/s in the +x direction. How fast and in what direction is the 1.5-kg cart traveling after the collision?