Compare this lab to some of the exercises in Section 3.7. The dependent variables are voltage across the capacitor and the current. In most circuit theory texts, this system is immediately converted into a second-order equation. This lab is meant to emphasize this point and to help our engineering students make the connection between our approach and what they are learning in their circuit theory class. This lab can be paired with Lab 4.1.
Some students have difficulty distinguishing external forces from restoring forces.
Also, some students identify anything that oscillates as a harmonic oscillator. On the other hand, other students will produce some very clever models. A Baby Bottle Harmonic Oscillator Baby bottles are fairly foreign to the everyday life of most students in this course. The point of including the lab is that systems that can be modeled using the harmonic oscillator really do occur in unlikely places. Students who have tried this lab have had difficulty obtaining useful data.