Answer: Their final relative velocity is -0.412 m/s.
Step-by-step explanation:
According to the law of conservation,
![m_(1)v_(1) + m_(2)v_(2) = (m_(1) + m_(2))v](https://img.qammunity.org/2021/formulas/physics/college/350onkewyscgbtifyl4ofvdxyxni0jg439.png)
Putting the given values into the above formula as follows.
![m_(1)v_(1) + m_(2)v_(2) = (m_(1) + m_(2))v](https://img.qammunity.org/2021/formulas/physics/college/350onkewyscgbtifyl4ofvdxyxni0jg439.png)
![2.50 * 10^(3) kg * 0 m/s + 7.50 * 10^(3) kg * -0.550 m/s = (2.50 * 10^(3) kg + 7.50 * 10^(3) kg)v](https://img.qammunity.org/2021/formulas/physics/college/f5irj5t9j2o90khed5jf7ki5pqq3f4nkm2.png)
![-4.12 * 10^(3) kg m/s = (10^(4) kg) v](https://img.qammunity.org/2021/formulas/physics/college/miq7f2nwpf8epoh5u8s3j2oi7nfuco467k.png)
v =
![(-4.12 * 10^(3) kg m/s)/(10^(4) kg)](https://img.qammunity.org/2021/formulas/physics/college/b5du6n2mrjkdthcztsm8mf7b15hr9xdki7.png)
= -0.412 m/s
Thus, we can conclude that their final relative velocity is -0.412 m/s.