Answer
$v_{sp}=5.11$ m/s
Work Step by Step
We solve for the average speed as follows:
$S_{ToT}=S_{AB}+S_{BC}+S_{CA}$
$S_{ToT}=20(\frac{\pi}{2})+\sqrt{20^2+30^2}+30+20$
$S_{ToT}=117.47$ m
$t_{Tot}=t_{AB}+t_{BC}+t_{CA}$
$t_{Tot}=5+8+10$
$t_{Tot}=23$ s
$v_{sp}=\frac{S_{Tot}}{t_{Tot}}=\frac{117.47}{23}=5.11$ m/s
