## College Physics (4th Edition)

(a) The total distance when traveling from Killarney to Mallow and then to Cork is $39~km + 22~km$ which is $61~km$. $average ~speed = \frac{distance}{time}$ $average ~speed = \frac{61~km}{48~min}$ $average ~speed = \frac{61,000~m}{(48)(60~s)}$ $average ~speed = 21.2~m/s$ (b) We can find the magnitude of the displacement: $\sqrt{(39~km)^2+(22~km)^2} = 44.8~km$ $average~velocity = \frac{displacement}{time}$ $average ~velocity= \frac{44,800~m}{(48)(60~s)}$ $average ~velocity= 15.6~m/s$ The magnitude of the average velocity is 15.6 m/s