With an acceleration of 4.0 m/s², the bottle attains a speed of
(4.0 m/s²) * (9.0 s) = 36 m/s
so that the slide has length ∆x such that
(36 m/s)² - 0² = 2 * (4.0 m/s²) * ∆x
==> ∆x = 162 m ≈ 160 m
Alternatively, we know the bottle covers a distance ∆x with acceleration a at time t according to
∆x = 1/2 a t²
so that
∆x = 1/2 * (4.0 m/s²) * (9.0 s)² = 162 m ≈ 160 m