SMT 2010 General #9
Source:
February 11, 2012
geometric series
Problem Statement
A straight line connects City A at to City B, 300 meters away at . At time , a bullet train instantaneously sets out from City A to City B while another bullet train simultaneously leaves from City B to City A going on the same train track. Both trains are traveling at a constant speed of meters/second. Also, at , a super
y stationed at and restricted to move only on the train tracks travels towards City B. The
y always travels at 60 meters/second, and any time it hits a train, it instantaneously reverses its direction and travels at the same speed. At the moment the
trains collide, what is the total distance that the y will have traveled? Assume each train is a point
and that the trains travel at their same respective velocities before and after collisions with the y