Three carts of masses Three carts of masses m1=6.0 kg, m2=12.0 kg, and m3=5.0 kg move on africtionless horizontal track with speeds of v1 =5.0 m/s, v2 =3.0 m/s, and v3 =-4.0 m/s,as shown in Figure . The carts stick together after colliding. Find the final velocity of the three carts after collision?