A strict theory of reciprocal influence of the contact deformation and
molecular attraction of a ball and a plane has been developed- It has
been shown that despite the van der Waals' forces being capable of in
creasing the elastic contact area between the ball and the plane, the
force that is required to overcome the molecular forces arising when t
he contact is broken does not increase thereby. In fact, it remains eq
ual to the attraction force value that is determined when considering
the point contact of a nondeformed ball with a plane. In the absence o
f the electrostatic component, the adhesion force is equivalent to the
first power of the bail radius and to the amount of work per unit are
a as required for effecting the equilibrium tearing-off of a flat surf
ace of the same nature.