A car moving East out of velocity of 25.8 m/s collides with a stationary truck with exactly twice the mass. If the two vehicles lost together cuz with the velocity of their combined us is immediately after collision
I guess you mean they stuck together
momentum before = 25.8 * m + 0 * 2 m = 25.8 m
momentum after = V * (m +2 m) = 3 m V
momentum after = momentum before ( Newton #1)
3 m V = 25.8 m
V = 25.8 / 3 meters/second