FEEL

Framework for Electronic Enhancement of Laboratories

Friction

Background Information:

**The Physics:**

Static friction is defined by the inequality F_{s} ≤
μ_{s}N. The figure above illustrates the forces
that act on an object being pushed up an inclined plane. We
can visualize the normal force N (vector pointing up
perpendicular to the plane), the user-applied force F
(pointing right), static friction F_{s} (pointing in
the opposite direction of F in this case), and the force of
gravity G.

**Traditional Learning Methods:**

The fact that the static frictional force is described by an
inequality is the ultimate source of difficulty for many
students. Since all forces they have seen before are
described by ordinary equalities, they tend to set
F_{s} = F_{smax}. Depending on the problem,
students may not be able to realize their mistake.
If the force applied to an object is less than
F_{smax}, the use of the incorrect equality
F_{s} = F_{smax} yields a nonphysical result.
This dynamic component is necessary to understand this
phenomenon, however, it cannot be adequately illustrated in a
textbook.

Motivation:

When developing visuo-haptic simulators, we look for concepts that involve forces in order to present them from a novel perspective. We chose friction since we observed that students have difficulty applying the theoretical concepts to problems. To provide a different perspective on the forces that act on a block on an inclined plane, we developed a 3D visuo-haptic simulator.

Related Resources:

F. G. Hamza-Lup and W. H. Baird (2012) "Feel the Static and Kinetic Friction" EuroHaptics 2012, Part I, LNCS 7282, pp 181 192, 12-15 June, Tampere, Finland
[PDF]

©2013, Felix G. Hamza-Lup. Design by Shane Farrar.