# What is the speed of an object that travels from ( -1, 7,2)  to ( -3, 4,7 )  over 2 s?

Feb 14, 2016

$v = \sqrt{10}$

#### Explanation:

$\text{distance between two point is given as:}$
x=sqrt(Delta x^2+Delta y^2+ Delta z^2
$\Delta x = {x}_{2} - {x}_{1} = - 3 + 1 = - 2$
$\Delta y = {y}_{2} - {y}_{1} = 4 - 7 = - 3$
$\Delta z = {z}_{2} - {z}_{1} = - 3 - 2$=-5
x=sqrt((-2)^2⁺(-3)^2+(-5)^2)
$x = \sqrt{4 + 9 + 25}$
$x = \sqrt{40}$
$v = \frac{x}{t}$
$v = \frac{\sqrt{40}}{2}$
$v = \frac{\sqrt{4 \cdot 10}}{2} = 2 \cdot \frac{\sqrt{10}}{2}$
$v = \sqrt{10}$