Two particles, 1 and 2, move with constant velocities `v_1` and `v_2` along two mutually perpendicular straight lines toward the intersection point O. At the moment `t=0` the particles were located at the distances `l_1` and `l_2` from the point O. How soon will the distance between the particles become the smallest? What is it equal to?

Answer

`t_("min")=(v_(1)x_(1)+v_(2)x_(2))/(v_(1)^(2)+v_(2)^(2))," " s_("min")=(x_(1)v_(2)-x_(2)v_(1))/(sqrt(v_(1)^(2)+v_(2)^(2))`