Answer :
If there's no friction and the wagon is free to move, then its momentum changes by 600 kg-meters per second.
From Newton's Derivation:
Change in Momentum = Force * time
m(v - u) = F* t
Momentum Change = 200 N * 3 seconds
= 600 Ns or 600 Kg.m/s.
Change in Momentum = Force * time
m(v - u) = F* t
Momentum Change = 200 N * 3 seconds
= 600 Ns or 600 Kg.m/s.