Question

What is the speed of an object that travels from `( 8 , -3, 6 )` to `( -8 , -4 ,1 )` over `2 s`?

Answer 1

Speed of object is about `8.4` units per second

Explanation:

The distance between two points `(x_1,y_1,z_1)` and `(x_2,y_2,z_2)` is given by

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

Hence distance between `(8,-3,6)` and `(-8,-4,1)` is

`sqrt((-8-8)^2+(-4-(-3))^2+(1-6)^2)`

= `sqrt((-16)^2+(-1)^2+(-5)^2)`

= `sqrt(256+1+25)`

= `sqrt282`

= `16.793`

As a distance of `16.793` is covered in `2s`

speed of object is `16.793=8.397~=8.4` per second