Answer :

[tex] \Delta x = \frac{1}{2} a t^{2} [/tex]
[tex] 110 = \frac{1}{2} (a) (5.21)^{2} [/tex]
[tex] a = \frac{200}{5.21^{2}} [/tex]
[tex] a = 8.10 m/s^2 [/tex]