Answer
(a) $a = 2.68~m/s^2$
(b) $x = 134~m$
$x = 440~feet$
Work Step by Step
(a) We can convert the speed to units of m/s. So;
$v = (60~mph)(\frac{1609~m}{1~mi})(\frac{1~h}{3600~s}) = 26.8~m/s$
$a = \frac{v-v_0}{t} = \frac{26.8~m/s-0}{10~s}$
$a = 2.68~m/s^2$
(b) $x = \frac{1}{2}at^2 = \frac{1}{2}(2.68~m/s^2)(10~s)^2$
$x = 134~m$
We can convert this distance to feet. Therefore;
$x = (134~m)(\frac{3.28~feet}{1~m})$
$x = 440~feet$