Answer :

seriously this is fun dont know why u want me to enjoy this so ummmm hmmm lolololol  the equation for this would be s=vif+1/2at^2 so time is lets see plug it and vell vi=0 since it started from rest so s=1/2at^2 and plug it in the displacement and time 110=1/2 a 5.21^2 and solve it and u get 8.1m/s^2