An object is at rest at (4 ,1 ,2 )(4,1,2) and constantly accelerates at a rate of 7/5 m/s^275ms2 as it moves to point B. If point B is at (5 ,6 ,1 )(5,6,1), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Feb 2, 2018

The time is =2.72s=2.72s

Explanation:

The distance ABAB is

AB=sqrt((5-4)^2+(6-1)^2+(1-2)^2)=sqrt(1+25+1)=sqrt(27)mAB=(54)2+(61)2+(12)2=1+25+1=27m

Apply the equation of motion

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

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

The acceleration is a=7/5ms^-2a=75ms2

Therefore,

sqrt27=0+1/2*7/5*t^227=0+1275t2

t^2=10/7*sqrt27t2=10727

t=sqrt(10/7*sqrt26)=2.72st=10726=2.72s