Answer:
The total momentum is
![p__(T )} =(2400 -4 v_2) \ Dalton \cdot m/s](https://img.qammunity.org/2021/formulas/physics/college/3f5wmlkcg32i7wbtey8y3xeha636km9m8r.png)
Step-by-step explanation:
The diagram illustration this system is shown on the first uploaded image (From physics animation)
From the question we are told that
The mass of the first object is
![M_1 = 12 \ Dalton](https://img.qammunity.org/2021/formulas/physics/college/ok0i1g6mu52hwua12bxsyrs6ccnyv0o87i.png)
The speed of the first mass is
![v_1 = 200 \ m/s](https://img.qammunity.org/2021/formulas/physics/college/2zfyc3i0bd52w6etyax3ghubswr13pvlhn.png)
The mass of the second object is
![M_2 = 4 \ Dalton](https://img.qammunity.org/2021/formulas/physics/college/v5j74e4is851ecapgiwh39jvp92666yu5g.png)
The speed of the second object is assumed to be
![- v_2](https://img.qammunity.org/2021/formulas/physics/college/wa7v187sz09551hfdz851gtyighvsrukeb.png)
The total momentum of the system is the combined momentum of both object which is mathematically represented as
![p__(T )} = M_1 v_1 + M_2 v_2](https://img.qammunity.org/2021/formulas/physics/college/wy2zstql4uh2w7wdwxomjtlieucbh6kl3p.png)
substituting values
![p__(T )} = 12 * 200 + 4 * (-v_2)](https://img.qammunity.org/2021/formulas/physics/college/pmi3vpdhfb0d7jhfhjp3lciku7d6p1y6y8.png)
![p__(T )} =(2400 -4 v_2) \ Dalton \cdot m/s](https://img.qammunity.org/2021/formulas/physics/college/3f5wmlkcg32i7wbtey8y3xeha636km9m8r.png)