Question

What is the speed of an object that travels from `( -2, -5, 1 )` to `( -5 , -7, 4 )` over `2 s`?

Answer 1

`approx 2.345 (units) /s`

Explanation:

In a Cartesian coordinate system distance d between two points `P_1(x_1, y_1, z_1)` and`P_2(x_2, y_2, z_2)` is given by the formula

`d=sqrt((x_2-x_1)^2+(y_2-y_1)^2+(z_2-z_1)^2)`

Inserting given values `(−2,−5,1)` and `(−5,−7,4)` for the points `P_1` and `P_2`

`d=sqrt((-5-(-2))^2+(-7-(-5))^2+(4-1)^2)`
`d=sqrt 22`
Now using the formula `speed = (dist ance)/(time)`
`d=sqrt 22/2`