Final answer:
The speeds mentioned are rates of travel for a car, commonly measured in miles per hour but convertible to meters per second, relevant in the subject of Physics for understanding motion and energy dynamics.
Step-by-step explanation:
The student is asking about the rate of travel when driving at different speeds measured in miles per hour. These speeds can often be more intuitively understood when converted into meters per second, as this is the standard unit of velocity in Physics. For instance, 55 mph is roughly 24.5872 m/s, 50 mph is about 22.352 m/s, and 60 mph translates to approximately 26.8224 m/s. It's worth noting that at highway speeds, over 50% of a car's power is used to overcome air drag, and fuel efficiency is often optimized around 70-80 km/h, which is around 45-50 mph. This information relates to broader concepts such as drag coefficients and fuel efficiency that are fundamental to understanding motion and energy in Physics.