pls help with this question i’ll give brainliest

Answer:
5m/s to the right
Explanation:
Momentum = mass * velocity
Momentum before = momentum after
m₁u₁+m₂u₂ = m₁v₁+m₂v₂
3000*10 + 1000*0 = 3000*v₁ + 1000*15
30000-15000=3000v₁
15000=3000v₁
v₁=5m/s to the right (to the right because answer is positive)