Question

Two ants, red ant and black ant, creeping along lines in 3-space. At time t, red ant is at point on the line

x=3-t , y-2=2t , z-2t=6

and at the same time t, black ant is at the point on the line

2x=t , y-3t=2 , z=2+t


a) Find the starting distance between red and black ants before they travel.
b) Is that possible red ant and black ant will collide each other? If yes, when and where will the collision happen?

Answer 1

red:
xr = 3 - t
yr = 2 + 2 t
zr = 6 + 2 t

black:
xb = t/2
yb = 2 + 3 t
zb = 2 + t

at t = 0
xb - xr = -3
yb - yr - 2-2 = 0
zb - zr = 2-6 = -4
so
d = sqrt(9+16) = 5 answer part a)

Answer 2

can
3-t = t/2 ?
only if
1.5 t = 3
t = 2
now when t = 2
2 + 2*2 = 2 + 3*2 whoops, no way