Solution1:
0.25 min = 15 secs
a = (v - [tex]v_{0}[/tex]) / t
v = 0 (stops to rest), t = 15
⇒ a = -[tex]v_{0}[/tex]/15
x = [tex]v_{0}[/tex]t + [tex]\frac{1}{2}[/tex]a[tex]t^{2}[/tex]
⇒ 10.5 = [tex]v_{0}[/tex] * 15 + [tex]\frac{1}{2}[/tex] * [tex]\frac{-v0}{15}[/tex] * 225
10.5 = [tex]v_{0}[/tex] * 15 -
10.5 = [tex]v_{0}[/tex] * 7.5
[tex]v_{0}[/tex] = 1.4 (m/s)
⇒ a = -[tex]\frac{7}{75}[/tex] (m/s^2)
Solution2: