## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

The formula $x = \frac{1}{2}at^2$ can be rearranged as: $t = \sqrt{\frac{2x}{a}}$ We now find the time for the Porsche to travel 400 m; $t = \sqrt{\frac{2x}{a}}$ $t = \sqrt{\frac{(2)(400~m)}{3.5~m/s^2}}$ $t = 15.1~s$ We then find the time for the Honda to travel 400 m; $t = \sqrt{\frac{2x}{a}}$ $t = \sqrt{\frac{(2)(400~m)}{3.0~m/s^2}}$ $t = 16.3~s$ Even with a 1.0 second head start for the Honda, the Porsche will win the race.