a) She reaches a velocity of 4 miles per hour at [tex]t = 5\,h[/tex].
b) The girl travels a distance of 6 miles in the first 3 hours.
c) The girl travels a distance of approximately 22.283 miles during her entire hike.
d) The average velocity of the girl is approximately 2.476 miles per hour.
a) The maximum velocity represent the maximum value in the vertical axis reached by the girl in time. According to the graph, she reaches a velocity of 4 miles per hour at [tex]t = 5\,h[/tex].
b) Travelled distance is represented graphically by the area below the curve and above the time axis. The travelled distance ([tex]\Delta x[/tex]), in miles, during the first 3 hours is represented by the area of a rectangle, that is to say:
[tex]\Delta x = v(3)\cdot \Delta t[/tex] (1)
Where:
- [tex]\Delta t[/tex] - Time interval, in hours.
- [tex]v(3)[/tex] - Final velocity, in miles per hour.
If we know that [tex]\Delta t = 3[/tex] and [tex]v(3) = 2[/tex], then the travelled distance in the first 3 hours is:
[tex]\Delta x = (2)\cdot (3)[/tex]
[tex]\Delta x = 6\,mi[/tex]
The girl travels a distance of 6 miles in the first 3 hours.
c) The travelled distance is determined by the following geometric expression:
[tex]\Delta x = v(3)\cdot t_{1} + 0.5\pi\cdot [v(5)-v(3)]^{2}+0.5\cdot v(3)\cdot (t_{2}-t_{1})[/tex] (2)
If we know that [tex]v(3) = 2[/tex], [tex]t_{1} = 7[/tex], [tex]v(5) = 4[/tex] and [tex]t_{2} = 9[/tex], then the travelled distance is:
[tex]\Delta x = 2\cdot 7 + 0.5\pi\cdot (4-2)^{2}+0.5\cdot 2\cdot (9-7)[/tex]
[tex]\Delta x \approx 22.283\,mi[/tex]
The girl travels a distance of approximately 22.283 miles during her entire hike.
d) The average velocity ([tex]\bar v[/tex]), in miles per hour, is obtained by dividing the traveled distance ([tex]\Delta x[/tex]), in miles, found in c) by time.
[tex]\bar v = \frac{\Delta x}{\Delta t}[/tex] (3)
If we know that [tex]\Delta x \approx 22.283[/tex] and [tex]\Delta t = 9[/tex], then the average velocity of the girl is:
[tex]\bar v = \frac{22.283}{9}[/tex]
[tex]\bar v \approx 2.476\,\frac{mi}{h}[/tex]
The average velocity of the girl is approximately 2.476 miles per hour.
To learn more on kinematics, we kindly invite to check this verified question: https://brainly.com/question/24486060
