Answer:
![83.65* 10^(-27)\ kg.m/s](https://img.qammunity.org/2022/formulas/physics/high-school/viy65rn5tb1592csf8jxvh13qejc1c6jis.png)
Step-by-step explanation:
Given
The velocities of the protons are 400 m/s and 450 m/s
Mass of the Proton is
![m=1.673* 10^(-27)\ kg](https://img.qammunity.org/2022/formulas/physics/high-school/6zgy8rqyesjns7rb99cs4weaxszhupql6b.png)
Since they travel in the opposite direction, therefore, their momentum cancels out each other.
Momentum is the product of mass and velocity
![\therefore m(450-400)\\\Rightarrow 1.673* 10^(-27)* 50\\\Rightarrow 83.65* 10^(-27)\ kg.m/s](https://img.qammunity.org/2022/formulas/physics/high-school/mvfvtihn91ai60b207p0vh2231xv2niv8s.png)
The direction of momentum is in the direction of proton having 450 m/s velocity.