What is the speed of an object that travels from #( -9,4,-6) # to #( -5,1,-2 ) # over #3 s#?

1 Answer
May 25, 2016

The speed is 2.13 m/s.

Explanation:

The distance between two points in the space is given by
#d=sqrt((x_1-x_2)^2+(y_1-y_2)^2+(z_1-z_2)^2)#.
This is the Pitagora's theorem in three dimensions.
The speed is simply the space (in this case the distance) divided by the time.

#d=sqrt((-9+5)^2+(4-1)^2+(-6+2)^2)=sqrt((-4)^2+3^2+(-4)^2)=sqrt(41)\approx 6.4 m#
#v=6.4/3\approx 2.13# m/s