PHYSICS · Subjective · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
At a certain instant a siren is at the origin. Four observers are 50 m east of the siren and move as follows:
• Observer A travels due east at 4 m/s.
• Observer B travels due west at 4 m/s.
• Observer C travels due north at 4 m/s.
• Observer D is stationary.
Identify any two observers who hear the same frequency at that instant, and state whether that frequency is higher than, lower than, or equal to the emitted frequency.