physics
posted by roger on .
Runner A is initially 9.0 mi west of a flagpole and is running with a constant velocity of 2.0 mi/h due east. Runner B is initially 5.0 mi east of the flagpole and is running with a constant velocity of 5.0 mi/h due west. How far are the runners from the flagpole when they meet?

v1•t+v2•t=s1+s2
t=(s1+s2)/(v1+v2) = 14/7 = 2 h.
v1•t=2•2=4 mi.
They met when they were 5 miles to the west from the flagpole