Final answer:
Janet's rate of 6.4 miles per hour represents her speed, which is reasonable for human running capabilities and doesn't involve acceleration as it is constant with no direction specified.
Step-by-step explanation:
When Janet runs 6.4 miles in one hour, we're discussing her speed, which is a scalar quantity indicating how fast an object is moving. Speed is calculated by dividing the total distance traveled by the time it takes to travel that distance. In contrast, velocity is a vector quantity, which means it includes both a magnitude (how fast an object moves) and a direction.
The average velocity would be the displacement (change in position) over time, which could be different from the speed if Janet does not run in a straight line. As for acceleration, this is the rate of change of velocity per unit of time, but since Janet's speed is constant, there is no acceleration mentioned in the scenario provided.