1. The problem statement, all variables and given/known data Three carts move on a frictionless horizontal track with different masses and speeds. Cart 1: 4 kg (5 m/s to the right) Cart 2: 10 kg (3 m/s to the right) Cart 3: 3 kg (4 m/s to the left) Cart 1 and 2 are right behind each other on the left side of the track while Cart 3 is by itself on the right side of the track. The carts stick together after colliding. Find the final velocity of the three carts. Answer in units of m/s. 2. Relevant equations Inelastic collision: Vf = v1(i) (m1/m1 + m2) 3. The attempt at a solution Since we know that the masses stick together after colliding, then we know this system is fully inelastic; therefore, we can use the above equation. Furthermore, we can say that Cart 1 and Cart 2 are one mass or m1 (4+10 = 14 kg) and Cart 3 is m2 (3 kg). So: Vf = v1(i) (14 kg/14 kg + 3 kg) vf = v1(i) (0.8235294118) However, I cannot figure out how to find the initial velocity of Cart 1 and 2 together.