Blip

About this episode

The reflection at a fixed end is inverted because the incoming pulse exerts a force on the rigid boundary that is opposite in direction to the reaction force the boundary exerts on the spring. The reflection at a free end is not inverted. If the mass density of the spring is μ1 and that of the boundary is μ2, then a fixed end reflection is modeled by μ2>>μ1 and vice-versa for a free end reflection. In the demonstration, a fixed end is accomplished by attaching the spring to the rod clamp while a free end is approximated by attaching the spring to a light string.

• Release Date

  Nov 6, 2008

• Runtime

  00:54