Runner A is initially 3.4 km west of a flagpole and is running with a constant velocity of 5.2 km/h due east. Runner B is initially 5.6 km east of the flagpole and is running with a constant velocity of 5.0 km/h due west. What will be the distance of the two runners from the flagpole when their paths cross?

1 answer

just working with the x-axis, or number line, the positions at time t are:

p(A) = -3.4 + 5.2t
p(B) = 5.6 - 5.0t

when they meet,

-3.4+5.2t = 5.6-5.0t
t = .88

p(A) = 1.18

so, the two runners are about 1.2 km east of the pole