Answer:
-8 Kgm/s
Explanation:
From the law of conservation of moentum, the sum of momentum before collision equals the sum of momentum after collision. Therefore
Before collision
Momentum =+15 kgm/s+-35 kgm/s=-20 kgm/s
After collision
Momentum=-12 kgm/s +x kgm/s
x-12 kgm/s=-20 kgm/s
x=-20+12=-8 Kgm/s