An atomic force microscope consists of a cantilever with a very fine tip on one end. The lever is driven by a piezoelectric motor allowing the tip to scan a surface on an atomic scale. As it scans the surface, what is the main frictional force between the tip and the surface?
A) static
B) kinetic
C) rolling
D) all three
E) There is no frictional force.

Question

Quizplus · Accepted Answer

The main frictional force between the tip and the surface will be kinetic friction because the tip is in motion as it scans the surface. Static friction would only come into play if the tip were initially at rest and needed to overcome a static friction force to start moving, which is not the case here. Rolling friction would not be a factor as there is no rolling motion involved in this setup.

An Atomic Force Microscope Consists of a Cantilever with a Very