A man traveling on a bicycle along a straight road that runs parallel to and right next to some railroad tracks. While moving at 10 m/s, he hears the whistle of a train that is behing him. The frequency emitted by the train's whistle is 820 Hz, but the frequency the man hears is 774 Hz. The speed of sound is 340 m/s.
A.) What frequency is heard by a stationary observer located between the train and the bicycle?
B.) What is the speed of the train, and is the train traveling away from or toward the bicycle?