A car slows down from 23 m/s to rest in a distance of 85 m. What was its acceleration, assumed constant?

Answer 1

v^2 = 2as
23^2 = 170a
a = -3.11 m/s^2
or,
23t + 1/2 at^2 = 85
23 + at = 0
a = -3.11