An object is at rest at (8 ,3 ,8 )(8,3,8) and constantly accelerates at a rate of 7/4 m/s^274ms2 as it moves to point B. If point B is at (6 ,5 ,2 )(6,5,2), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Dec 15, 2017

The time is =2.75s=2.75s

Explanation:

The distance ABAB is

AB=sqrt((6-8)^2+(5-3)^2+(2-8)^2)=sqrt(4+4+36)=(sqrt44)mAB=(68)2+(53)2+(28)2=4+4+36=(44)m

Apply the equation of motion

s=ut+1/2at^2s=ut+12at2

The initial velocity is u=0ms^-1u=0ms1

The acceleration is a=7/4ms^-2a=74ms2

Therefore,

sqrt44=0+1/2*7/4*t^244=0+1274t2

t^2=8/7sqrt44t2=8744

t=sqrt(8/7sqrt44)=2.75st=8744=2.75s