Imagine the case of a gecko adhered to the flat surface of an outdoor ceiling against the force of gravity outdoors on a typical day in San Diego. The adhesive pressure between two flat surfaces can be described by equation 3.6. (The closest any two materials can approach is D = 0.17 nm, but this value is not required to solve the problem.) Derive an expression for the total area of the gecko foot pads in contact with the ceiling that would be necessary to keep the gecko adhered against the force of gravity in terms of A, , D, the acceleration of gravity (g), and the mass of the gecko (m).