A state patrol officer saw a car start from rest at a highway on-ramp. She radioed ahead to another officer 23 mi along
the highway. When the car reached the location of the second officer 21 min later, it was clocked going 60 milhr. The
driver of the car was given a ticket for exceeding the 60 mi/hr speed limit. Why can the officer conclude that the driver
exceeded the speed limit?

To determine whether the driver exceeded the speed limit, we need to calculate the car’s average speed over the course of the journey. The car traveled 23 miles in 21 minutes. To convert the time from minutes to hours, we divide by 60, getting 0.35 hours. Next, we calculate the average speed by using the formula: speed = distance/time. This gives us an average speed of 23 miles / 0.35 hours = approximately 65.71 miles per hour. Since this average speed is greater than the posted speed limit of 60 miles per hour, the officer can conclude that the driver was indeed exceeding the speed limit.

Now, it’s important to note that the driver’s speed at the end (60 miles per hour) does not represent their overall average speed during the entire trip. This is a crucial point in traffic enforcement where average speed plays a role in determining compliance with speed regulations. Hence, even if the driver was clocked at the speed limit at one point, their average speed confirms the violation.