Final answer:
The speed limit in a marked school zone may be as low as 15, 20, 25, or 30 miles per hour. For the interstate highway speed, 80 km/h converts to about 22.2 m/s and 49.7 mi/h.
Step-by-step explanation:
The speed limit in a marked school zone, during the hours that students are present, may be as low as 15, 20, 25, or 30 miles per hour. These options reflect typical speed limits set to enhance safety in areas where children are likely to be crossing streets and sidewalks.
Speed limits are typically lower in school zones to create a safer environment for students. Turning to the second question, the speed limit on some interstate highways is roughly 80 km/h.
To convert this to meters per second, we use the formula 1 km/h = 0.277778 m/s, so 80 km/h is 22.2 m/s. In miles per hour, 80 km/h is approximately 49.7 mi/h. Hence, the correct answer for the conversion is option b.