Answer:
The average speed of the car, in miles per hour, from 17:30 to 19:42, is 119.167 meters per second.
Step-by-step explanation:
Physically speaking, average speed ([tex]\bar v[/tex]), measured in miles per hour, is the distance travelled ([tex]\Delta s[/tex]), measured in miles, divided by time ([tex]\Delta t[/tex]), measured in hours. That is:
[tex]\bar v = \frac{\Delta s}{\Delta t}[/tex] (1)
The time needed by the vehicle is:
[tex]\Delta t = 72\,min\times \frac{1\,h}{60\,min}[/tex]
[tex]\Delta t = 1.2\,h[/tex]
If we know that [tex]\Delta s = 143\,mi[/tex] and [tex]\Delta t = 1.2\,h[/tex], then the average velocity of the car is:
[tex]\bar v = \frac{143\,mi}{1.2\,h}[/tex]
[tex]\bar v = 119.167\,\frac{m}{s}[/tex]
The average speed of the car, in miles per hour, from 17:30 to 19:42, is 119.167 meters per second.
