The dog shakes to get the water off of him and to get dry. These fast movements replicate when we drain the water out of our hair and when we blow dry our hair.
Every mass is attracted to every other mass with a force that is proportional
to the product of both masses and inversely proportional to the square of the
distance between their centers of mass. The forces act along the line between
their centers of mass.
Six centimeters equal to about two inches