Answer:
d = 711 miles
Step-by-step explanation:
The speed s of the car is given by :
[tex]s=3\sqrt{d}[/tex] ...(1)
Where
d is the stopping distance
We need to find the stopping distance of a car travelling at 80 mph.
Rearranging equation (1) for d.
[tex]s^2=9d\\\\d=\dfrac{s^2}{9}\\\\d=\dfrac{80^2}{9}\\\\d=711.1\ miles[/tex]
or
d = 711 miles
So, the required stopping distance is 711 miles.