You are driving along a highway at 29.5 m/s when you hear the siren of an ambulance traveling in the opposite direction on the other side of the highway. When the vehicle is approaching you, you hear the frequency of the siren as 2600 Hz, but when it is past you the frequency becomes 1920 Hz. What is the speed of the ambulance? The speed of sound in air is 340.0 m/s.

and the second part:
What is the frequency of the ambulance's siren?

Question

You are driving along a highway at 29.5 m/s when you hear the siren of an ambulance traveling in the opposite direction on the other side of the highway. When the vehicle is approaching you, you hear the frequency of the siren as 2600 Hz, but when it is past you the frequency becomes 1920 Hz. What is the speed of the ambulance? The speed of sound in air is 340.0 m/s. 

and the second part:
What is the frequency of the ambulance's siren?

anonymous · Answer

Look up Doppler frequency shift rules.