An object is at rest at (1 ,3 ,9 )(1,3,9) and constantly accelerates at a rate of 7/474 ms^-2ms2 as it moves to point B. If point B is at (2 ,5 ,6 )(2,5,6), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Mar 23, 2016

The distance between the points (calculated below) is 3.743.74 mm. Then d=ut+1/2at^2=0(t)+1/2(7/4)t^2.d=ut+12at2=0(t)+12(74)t2. Rearranging, 7/8t^2=3.74 to t = 2.1 s78t2=3.74t=2.1s.

Explanation:

To find the distance between the points:

d=sqrt((x_2-x_1)^2+(y_2-y_1)^2+(z_2-z_1)^2)d=(x2x1)2+(y2y1)2+(z2z1)2
=sqrt((2-1)^2+(5-3)^2+(6-9)^2)=(21)2+(53)2+(69)2
=sqrt(1+4+9)=sqrt14~~3.74=1+4+9=143.74 mm.