An object is at rest at (2 ,8 ,6 ) and constantly accelerates at a rate of 5/3 m/s^2 as it moves to point B. If point B is at (3 ,2 ,7 ), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Aug 15, 2017

The time is =2.11s

Explanation:

The distance AB is

AB=sqrt((3-2)^2+(2-8)^2+(7-6)^2)=sqrt((1)^2+(-6)^2+(1)^2)

=sqrt(1+36+1)=sqrt38m

The acceleration is a=5/3ms^-2

The initial velocity is u=0ms^-1

We apply the equation of motion

s=ut+1/2at^2

So,

sqrt38=0+1/2*(5/3)^2*t^2

t^2=18/25sqrt38

t=sqrt(18/25sqrt38)=2.11s