The powerpoint presentation below summarizes sections 15.1 - 15.6. It also includes many links to other helpful websites.
Figure 15.4 on p. 389 is the vertical alignment of displacement, velocity and acceleration of simple harmonic motion. I call it the "picture worth 1,000 words". You can print out a copy below, titled "disp_vel_acc_SHM"
Download the Excel file below to change parameters of the cosine wave equation to see how each variable affects the shape of the graph. Or try this website (requires Java).
Videos
Sine wave / Cosine wave animation (as it relates to circular motion)
Measuring K constants of springs using Hooke's Law and finding the new K constant when the springs are joined together. Also compares measured periods of oscillation to the calculated value using the equation for period of a spring.