Two objects $\mathrm{A}$ and $\mathrm{B}$ move at a constant speed of $4 \mathrm{m} \mathrm{s}^{-1}$ along a circular path. What is the relative velocity of $\mathrm{B}$ (magnitude and direction) with respect to $\mathrm{A}$ when the objects are in the positions shown in Figure $1.14 ?$