The mariana trench is the deepest ocean trench on. this trench occurs at a plante boundary where

The Mariana Trench is part of the Izu-Bonin-Mariana subduction system that forms the boundary between two tectonic plates. In this system, the western edge of one plate, the Pacific Plate, is subducted (i.e., thrust) beneath the smaller Mariana Plate that lies to the west.

Explanation:

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

f=ma newton's second law 7x8=56n