Answer
(a) see graph
(b) t = 21.9 s
(c) $a = 3.54 m/s^2$
(d) v = 77.5 m/s
Work Step by Step
(a) see graph
(b) We can convert the speeder's speed to m/s.
$(140~km/h)(\frac{1000~m}{1~km})(\frac{1~h}{3600~s}) = 38.9~m/s$
$t = \frac{d}{v} = \frac{850~m}{38.9~m/s} = 21.9~s$
(c) $x = \frac{1}{2}at^2$
$a = \frac{2x}{t^2} = \frac{(2)(850~m)}{(21.9~s)^2}= 3.54~m/s^2$
(d) $v = at = (3.54~m/s^2)(21.9~s) = 77.5~m/s$
