##2.3s## (2sf), Assuming dropped from rest vertically with no air resistance.
Assuming that we are treating the clam as falling vertically from rest with no air resistance, the following should sort it:
Downwards is positive.
##s=27m##
##u=0ms^-1##
##v=vms^-1##
##a=g=9.81ms^-2##
##t=?s##
We are looking for ##t##, and with the information we have, we don’t need to worry about ##v##.
Use the constant equation:
##s=ut+1/2at^2##
##27=1/2(g)t^2##
##t^2=54/9.81##
##t=2.34618….s##
##t=2.3s## (2sf)
