Answer:
[tex]\Delta r=-1.71m[/tex] It moves 1.71m to the left.
Explanation:
The intial position of the center of mass is:
[tex]ro = \frac{m_J*r_J+m_B*r_B}{m_J+m_B} =7.05m[/tex]
The final position of the center of mass is:
[tex]rf = \frac{m_J*r_B+m_B*r_J}{m_J+m_B} =5.34m[/tex]
The displacement between these positions is:
Δr = 5.34m - 7.05m = -1.71m
This means it moves 1.71m to the negative x-axis