An object is at rest at (1 ,5 ,1 ) and constantly accelerates at a rate of 4/3 m/s^2 as it moves to point B. If point B is at (9 ,4 ,8 ), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Apr 16, 2016

t~=4" s"

Explanation:

A=(1,5,1)" the point of A"

B=(9,4,8)" the point of B"

A_x=1" "A_y=5" "A_z=1

B_x=9" "B_y=4" "B_z=8

"let's calculate distance between the points A and B"

Delta s=sqrt((B_x-A_x)^2+(B_y-A_y)^2+(B_z-A_z)^2)

Delta s=sqrt((9-1)^2+(4-5)^2+(8-1)^2)

Delta s=sqrt(8^2+(-1)^2+7^2)

Delta s=sqrt(64+1+49)

Delta s=10,68" m"

a=4/3 m/s^2 "acceleration of object"

t="elapsed time from the point of A to the point of B"

Delta s=1/2 *a*t^2
"distance equation for an object moving from rest"

10,68=1/2*4/3*t^2

t^2=(3*10,68)/2

t^2=16,02

t~=4" s"