If a cell phone is dropped from a very tall building, how far has the phone fallen after 2.7 seconds, neglecting air resistance?

The free fall of the phone is an uniformly accelerated motion toward the ground, with constant acceleration equal to


So, assuming the downward direction as positive direction of the motion, since the phone starts from rest the distance covered by the phone after a time t is given by

And if we substitute t=2.7 s, we find the distance covered: