An object is at rest at $(1 ,7 ,4 )$ and constantly accelerates at a rate of $5/4 m/s^2$ as it moves to point B. If point B is at $(8 ,5 ,3 )$ , how long will it take for the object to reach point B? Assume that all coordinates are in meters.

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Answer 1 · 2016-03-30T12:47:14

$t=3,43 "s"$

$"distance between (1,7,4) and (8,5,3):"$

$s=sqrt((8-1)^2+(5-7)^2+(3-4)^2)$

$s=sqrt(7^2+(-2)^2+(-1)^2)$

$s=sqrt(49+4+1)$

$s=sqrt54$

$s=7,35 " m"$

$a=5/4=1,25 " "m/s^2$

$t=?$

$s=1/2*a*t^2$

$t^2=2*s/a$

$t^2=(2*7,35)/(1,25)$

$t^2=11,76$

$sqrt (t^2)=sqrt (11,76)$

$t=3,43 "s"$

An object is at rest at (1 ,7 ,4 )(1 ,7 ,4 ) and constantly accelerates at a rate of 5/4 m/s^25/4 m/s^2 as it moves to point B. If point B is at (8 ,5 ,3 )(8 ,5 ,3 ), how long will it take for the object to reach point B? Assume that all coordinates are in meters.