## Essential University Physics: Volume 1 (3rd Edition)

We know that the average velocity is given as (a) $v=\frac{r_2-r_1}{\Delta t}$ We plug in the known values to obtain: $v=\frac{(4.6i+1.9k)-(2.2i+3.7j-1.2K)}{6.2}$ $v=\frac{2.4i-3.7j+3.1k}{6.2}$ $v=0.39i+0.60j+0.50k \space \frac{\mu m}{s}$ (b) The average speed is $v=\sqrt{(0.39)^2+(0.60)^2+(0.50)^2}$ $v=0.87\frac{\mu m}{s}$