A train starts from rest at your stationary position and heads directly away from you. It accelerates at a constant 0.50 m/s2. The conductor blows the horn, which she perceives as having a frequency of 455 Hertz. Determine how far away is the train at the moment when you hear a frequency of 435 Hertz? Hint: Remember that it takes time for the sound of the train's horn to reach you.