If a bus travels 12.0 km south then 5.0km north in 0.25 hr, what is its average velocity?
\(\text{You use the word velocity. Velocity is a vector.}\\ \text{Using a coordinate system where north is positive }y \text{ and east is positive }x \text{ we have}\\ \vec{v} = \dfrac{-12\hat{j} + 5\hat{j}}{0.25}= -28\hat{j}~km/hr\)