In October 1997, Andy Green broke the sound barrier on land in a jet-powered car traveling at \(763 \mathrm{mi} / \mathrm{h}\) over a \(1.0-\mathrm{mi}\) course. As it arrived at the beginning of this measured mile, Green's car had accelerated from rest to \(763 \mathrm{mi} / \mathrm{h}\) over a \(5.0-\mathrm{mi}\) stretch.

(a) What was Green's average acceleration in that \(5.0 \mathrm{mi}\) ?

(b) Calculate the time interval needed for Green to reach his maximum speed.