Final answer:
The distance at which the amber lights of the bus will flash before stopping is calculated using the stopping distance formula.
Step-by-step explanation:
To determine how far in advance the amber lights will flash before a bus comes to a complete stop, we need to calculate the stopping distance of the bus.
Given that the bus decelerates uniformly over 5 seconds to a stop, we can use the formula s = ut + (1/2)at2, where s is the distance, u is the initial speed, a is the acceleration (deceleration in this case should be taken as negative), and t is the time. With the initial speed being 20 m/s (the speed before deceleration) and the time being 5 seconds, we need the deceleration rate.
The deceleration can be found using the formula v = u + at, where v is the final velocity (0 m/s since the bus stops). When we rearrange this for a, we get a = (v - u) / t. Plugging in our values, the deceleration is -4 m/s2.
Now, substituting u = 20 m/s, a = -4 m/s2, and t = 5 s into the first formula, we calculate the stopping distance to be 50 meters. Therefore, the amber lights will flash 50 meters before the bus comes to a complete stop. This helps ensure that vehicles and pedestrians are aware of the bus's intention to stop and can react accordingly.
Noting the approach speed and stopping time can be vital in various situations, like when hearing a Doppler shift in an ambulance siren to know when to give way. Similarly, in a different context, understanding the movement and signals is essential for traffic safety to avoid incidents, like running a red light regardless of the situation, unless in an ethical dilemma as posed by the Rule Utilitarianism (RU) scenario provided.