{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# Sec 7.6 - 7 Waves Sound Radio and Light I do not think that...

This preview shows pages 1–3. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
218 The Silicon Web: Physics for the Internet Age 7.2 SIMPLE HARMONIC MOTION A grandfather, or pendulum, clock “counts” time by the number of oscillations the pendulum makes. The simplest pendulum clock is in Figure 7.1 , showing a metal ball (called a bob) fi xed to a rigid rod that is swinging from a low-friction pivot. When at rest, the bob is in the equilibrium position. When set into motion, the bob moves back and forth along an arc. The center picture shows the motion of the bob just after it has been set into motion. The distance the bob travels between its center position and its extreme position is called the amplitude of the motion. Remarkably, the time it takes for the bob to move between its two extreme positions is nearly the same regardless of whether the amplitude is small or is large. The story goes that 17-year-old Galileo noticed this behavior while in church, watching the motion of a swinging chandelier. As the service wore on, the pendulum’s amplitude grew smaller, yet the time between the plate reaching its extreme position remained the same (he timed the pendulum’s motion using his own heartbeat). If we graph the horizontal position of the pendulum versus time, we see a curve as shown in Figure 7.2 . By horizontal position, we mean the position of a shadow on the fl oor below the bob that would be produced by shining a light from above the pendu- lum. The shadow would move back and forth along a straight line. At any instant of time, the shadow’s distance from the equilibrium position would be given by the value of the oscillating curve shown in the graph. Any curve with this specifi
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 54

Sec 7.6 - 7 Waves Sound Radio and Light I do not think that...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online