Forces

It is interesting to see the interplay of forces relative to the trajectories of these aircraft landing in Dusseldorf, Germany.

About pendulum periodicity

Chapter 15 has a nice diagram about the forces on a pendulum mass, Fig. 15-3, I think. We treat a pendulum just as if it were a spring IF its amplitude of oscillation is only a few degrees left and right of vertical.

I just activated a new page, "Why a pendulum behaves periodically, like a spring." It has a bunch of diagrams, for those of you who want some extra depth of knowledge. No trig, no calculus, just proportional right triangles. Look for this in the Lecture Files.

Uvision, new podcasts

There are four new visual podcasts at Uvision. Three of them are about forces, chapter 3 and chapter 4 concepts.