Final answer:
When an emergency vehicle approaches with sirens and lights flashing, you must pull over to the side of the road and stop if necessary. The Doppler shift of the siren helps you identify the vehicle's approach. The frequency heard matches the actual siren's frequency when the vehicle is directly in front of you.
Step-by-step explanation:
What to Do When an Emergency Vehicle Approaches
When encountering an emergency vehicle with sirens and flashing lights, it's important to take immediate action to ensure the safety of all road users and facilitate the emergency vehicle's quick passage. As a driver, when you hear the Doppler shift in the siren, indicating the vehicle is approaching, you must pull over to the side of the road and stop if necessary, making sure you are clear of intersections. Do not block any pathways that the emergency vehicle may need to use. Once the emergency vehicle has passed, you can proceed with caution.
In addition to the immediate response to an emergency vehicle, certain principles like Rule Utilitarianism (RU) suggest that, in other scenarios such as driving a pregnant woman in labor to the hospital, going through a red light at 4 am when no other vehicles are present may be ethically justifiable if it results in more utility or good than following the law strictly would. Applying the RU concept here involves critical thinking and an understanding of when it is morally appropriate to bend certain rules for the greater good.
GRASP CHECK - Understanding Doppler Shift
Regarding the Doppler shift, when standing on the sidewalk, the frequency of the ambulance siren that you hear will most closely match its actual frequency when the ambulance is directly in front of you—this is because the sound waves are neither compressing (as when the source approaches) nor stretching (as when it moves away).