an elevator car whose floor to ceiling distance is equal to 2.7m starts from rest with a constant acceleration of 1.2 ms^-2 . two seconds later , a bolt drops from car's ceiling.the time taken by bolt to hit floor of elevtor is..plz say..

mention whether elevator is going up or down

this problem will be easier if u solve it in frame of elevator

when bolt gets detached its initial  velocity w.r.t. elevator is 0

a_bE = a_b(g) - a_E(g)

       =g - a               if elevator is going down taking down +ve

      or    g+a                "   "      "      "        "  up     "        "      "

 now   2.7 = u_{bE t   +}   a_bEt²/2

             = 0  +   a_bEt²/2 

   imp - block moves 2.7 w.r.t elevator