
So, $\vec{\text{v}}_{\text{c}}=\frac{\text{m}_1\vec{\text{v}}_1+\text{m}_2\vec{\text{v}}_2+\text{m}_3\vec{\text{v}}_3+\text{m}_4\vec{\text{v}}_4+\text{m}_5\vec{\text{v}}_5}{\text{m}_1+\text{m}_2+\text{m}_3+\text{m}_4+\text{m}_5}$ $=\frac{1(-1.2\hat{\text{i}}-0.9\hat{\text{j}})+1.2(0.4\hat{\text{j}})+1.5(-0.8\hat{\text{i}}+0.6\hat{\text{j}})+0.5(3\hat{\text{i}})+1(1.6\hat{\text{i}}-1.2\hat{\text{j}})}{5.2}$ $=\frac{-1.2\hat{\text{i}}-0.9\hat{\text{j}}+4.8\hat{\text{j}}-1.2\hat{\text{i}}+0.90\hat{\text{j}}+1.5\hat{\text{i}}+1.6\hat{\text{i}}-1.2\hat{\text{i}}}{5.2}$ $=\frac{0.7\hat{\text{i}}}{5.2}-\frac{0.72\hat{\text{j}}}{5.2}$