# What is the speed of an object that travels from ( 1,-4,6)  to ( 0,-9,2)  over 3 s?

$v = \frac{\sqrt{42}}{3} \text{ } \frac{m}{s}$
$\text{distance between the given points is: } \Delta s = \sqrt{{1}^{2} + {5}^{2} + {4}^{2}}$
$\Delta s = \sqrt{1 + 25 + 16} = \sqrt{42} \text{ units}$
$v = \frac{\Delta s}{\Delta t}$
$v = \frac{\sqrt{42}}{3} \text{ } \frac{m}{s}$