11.2 Graphs of Harmonic Motion

Unit 4: Sound and Waves

Reading Harmonic Motion Graphs

Seeing a pattern of cycles on a graph is an indication that harmonic motion is present

Periodic motion: graphs repeat every period (from crest to crest)

Amplitude on a graph Distance between highest and lowest

pointsPeriod of a graph

Time difference between the beginning of the cycle and the end

CIRCLES AND HARMONIC MOTION

Cycles of circular motion always have a length of 360 degrees

Phase: where the oscillator is in its cycle

11.3 SIMPLE MECHANICAL OSCILLATORS

Pendulum Force that always pulls

the pendulum back to the center comes from its weight

Spring Springs of a car are

compressed and extended in rhythmic patterns

String Such as a guitar string,

it will vibrate and make waves

Scientist Spotlight

Katherine Johnson Born in 1918 Hired as a mathematician by

a government agency that became NASA

Determined trajectories for manned and unmanned spacecraft▪ Helped plan the Apollo missions

and developed their emergency navigation system