Reading Guide
for February 25

Chapter 19: Vibrations and Waves

pp. 362. Vibration of a Pendulum.   We will not specifically address pendulums in class, because time is short.  So you may as well simply skip this section.

pp. 363–365. Wave Description.   The first part of this section briefly discusses simple harmonic motion, to which we will devote some lecture time.

p. 363. footnote 2.  Read this carefully.  This footnote states the conditions for simple harmonic motion and gives the formula for Hooke’s law.

• What is the formula for Hooke’s law?
• What is the connection between Hooke’s law and simple harmonic motion?
• What is the relationship between simple harmonic motion and vibrations?

There is one paragraph (and Figure 19.3) describing the motion of a bob on a spring.

• Why does this oscillation follow simple harmonic motion?

There is also a lot of important vocabulary in this section.  Be able to define:

• amplitude
• wavelength
• frequency
• hertz
• period

Also understand the relationship between period and frequency.

Recommmended workbook exercise:  p. 81.

Reflection

Why does an oscillating object move through its center position, where the Hooke’s law force acting on it is zero?