To solve the problem it is necessary to apply the conservation equations for the moment, specifically for collision. In addition to that, the concepts of vector velocity are necessary, in which the components are obtained and if the total magnitude is necessary.
Conservation of Momentum equation is given by,
[tex]m_1v_1+m_2v_2+m_3v_3 = 0[/tex]
We need to find the speed 3, therefore by readjusting the equation we have,
[tex]v_c = \frac{-(m_1v_1+m_2v_2)}{m_3}[/tex]
[tex]v_c = \frac{-(-70*2\hat{j}-85*2.5\hat{j})}{80}[/tex]
[tex]v_c = 2.656\hat{i}+ 1.75\hat{j}[/tex]
Therefore the components of the velocity would be,
[tex]v_{cx} = 2.656m/s[/tex]
[tex]v_{cy} = 1.75m/s[/tex]