Answer:
The change in momentum is 2 times the length of the momentum vector put in the negative direction.
Explanation:
The change in momentum is defined as
[tex]\Delta p=p_f-p_i[/tex]
meaning it is the difference between the final and the inital momentum.
Now, our initial momentum is
[tex]p_i=mv_i\vec{i}[/tex]
it is in the positive i-direction.
The final momentum is
[tex]p_f=-mv_i\vec{i}[/tex]
and it is in the negative i-direction.
Therefore, the change in momentum is
[tex]\Delta p=p_f-p_i=p_f=-mv_i\vec{i}-mv_i\vec{i}[/tex][tex]\boxed{\Delta p=-2mv_i\vec{i}}[/tex]
which is our answer!
Now, what is the direction and magnitude of this momentum vector?
This vector has length 2 and points in the negative i-direction.
