Answer
The total momentum of the two blocks after the collision is $2.0~kg~m/s$
Work Step by Step
We can find the initial momentum of the 2.0 kg block:
$p_0 = mv = (2.0~kg)(1.0~m/s) = 2.0~kg~m/s$
By conservation of momentum, the final momentum of the system just after the collision is equal to the initial momentum of the 2.0 kg block.
The total momentum of the two blocks after the collision is $2.0~kg~m/s$.