Let d represents the stopping distance required by an alfa romeo.
The stopping distance is proportional to the square of velocity is equivalent to the equation,
[tex]d=kv^2[/tex]
Here, k is proportionality constant.
Given, d = 177 feet and v = 70 mph.
So, proportionality constant
[tex]k=\frac{177\ feet }{(70\ mph)^2} \simeq 0.0361[/tex].
Thus, the stopping distances required by an alfa romeo going at 60 mph and at 140 mph,
[tex]d_{60mph} =0.0361 \times (60\ mph)^2 =129.96\ feet[/tex]
and
[tex]d_{140mph} =0.0361 \times (140\ mph)^2 =707.56\ feet[/tex]