Hello everyone! I need some help with a Doppler effect/relative motion question. 1. The problem statement, all variables and given/known data A whistle with a frequency of 1200 Hz is travelling south at a velocity of 30.0 m/s. You are travelling north away from the whistle at a speed if 18.0 m/s. If the speed of sound is 340 m/s, what is the apparent frequency of the whistle as heard by you? (Answer: 1044 Hz) 2. Relevant equations f=(v/v+vs)fs 3. The attempt at a solution Relative to myself, the train is moving at a speed of 48 m/s south and therefore away from me. Using the aforementioned equation I calculated frequency at 1051 Hz. Is the answer key wrong or am I missing something?