Answer: Average Velocity=0, Average speed=4mph
Explanation:
Let's begin by stating clear that motiont is the change of position of a body at a certain time. So, during this motion, the Amaya will have a trajectory and a displacement, being both different:
The trajectory is the path followed by Amaya, the distance it travelled (is a scalar quantity).
The displacement is the distance in a straight line between the initial and final position (is a vector quantity).
On the other hand, the velocity is a vector quantity and speed is its magnitude (a scalar quantity).
So, since Amaya ran around a closed track, the distance between her initial position and final position is zero, hence her average velocity is zero [tex]V_{avg}=0[/tex].
Now, in the case of her average speed [tex]S_{avg}[/tex], this can be calculated by the following equation:
[tex]S_{avg}=\frac{d}{t}[/tex]
Where:
[tex]d=1\frac{mile}{track} 3 tracks=3 miles[/tex] is the covered distance (the trajectory)
[tex]t=45 min \frac{1 h}{60 min}=\frac{3}{4}h=0.75 h[/tex] is the time it took to Amaya to cover the mentioned distance
Then:
[tex]S_{avg}=\frac{3 miles}{0.75 h}[/tex]
Finally:
[tex]S_{avg}=4 \frac{miles}{h}=4 mph[/tex]
