Answer:
screw and pulley
Explanation:
because they didn't have any of the other tools in that time
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: