Two objects, $A$ and $B$, collide. A has mass $2.0 \mathrm{~kg}$, and $B$ has mass $3.0 \mathrm{~kg}$. The velocities before the collision are $\overrightarrow{\mathbf{v}}_{\mathrm{iA}}=$ $(15 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{i}}+(30 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{j}}$ and $\overrightarrow{\mathbf{v}}_{\mathrm{i} B}=(-10 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{i}}+(5.0 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{j}}$
After the collision, $\overrightarrow{\mathbf{v}}_{\mathrm{fA}}=(-6.0 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{i}}+(30 \mathrm{~m} / \mathrm{s}) \hat{\mathbf{j}}$. What is
the final velocity of $B$ ?