Final answer:
The minimum speed on the left-most lane of an interstate varies, but when the speed limit is 100 km/h (62 mph), the minimum is usually around 40-45 mph. This ensures smooth traffic flow and safety.
Step-by-step explanation:
The minimum speed on the left-most lane on an interstate highway is not universally fixed and can vary by state and roadway. However, interstate highways often have posted minimum speed limits to ensure traffic flows smoothly. For example, if the speed limit is 100 km/h, which is approximately 62 miles per hour (since 1 mile is about 1.609 kilometers), the minimum speed is often around 40-45 mph to keep up with the flow of traffic and ensure safety. This minimum speed helps prevent slower vehicles from causing accidents or impeding the flow of faster-moving traffic in the left lane, which is traditionally reserved for overtaking.
In the instances provided, the speed conversions would be essential to know if a driver is within the legal limits. Converting from kilometers to miles or meters per second into miles per hour can help a driver determine if they are exceeding or under the minimum speed limits.