Problem $11\mathrm{.}119-$ Relative motion of particles with constant velocities

Three seconds after automobile $B$ passes through the intersection shown, automobile A passes through the same intersection. Given, the speed of automobile $A$ is $v_A=75\mathrm{.}0m\frac{i}{h}$ and automobile $B$ is $v_B=42\mathrm{.}00m\frac{i}{h},$ respectively. Also, know that the speeds are constant for the automobiles during the encounter.

Problem $11\mathrm{.}119.$a $-$ Relative motion of particles with constant velocities$-$find relaitve velocity

Determine the relative velocity of $B$ with respect to $A.$

The relative velocity of $B$ with respect to $A$ is $f\frac{t}{s}$ at an angle of $$