Measuring Simple Harmonic Motion amplitude—the maximum displacement from equilibrium. (how high or...

Measuring Simple Harmonic MotionMeasuring Simple Harmonic Motion

amplitude—the maximum displacement from equilibrium. (how high or low the wave gets) Doesn’t affect the speed of the wave.

frequency—the number of cycles/waves per unit of time.

Can be mentioned as revolutions, vibrations, oscillations, etc.

period—the time it takes to execute a complete cycle of motion.


•The period of a simple pendulum depends on pendulum length and local gravitational acceleration

Period of a Simple Pendulum in Simple Harmonic Motion


Period of a Mass Spring System in Simple Harmonic Motion

The period of a spring depends on the mass on the end and the stiffness (k) of the spring.

Section 12-3 ObjectivesSection 12-3 ObjectivesProperties of WavesProperties of Waves

1.1. Distinguish local particle vibrations from Distinguish local particle vibrations from overall wave motion. overall wave motion.

2.2. Differentiate between pulse waves and Differentiate between pulse waves and periodic waves. periodic waves.

3.3. Interpret waveforms of transverse and Interpret waveforms of transverse and longitudinal waveslongitudinal waves

4.4. Apply the relationship among wave speed, Apply the relationship among wave speed, frequency, and wavelength to solve problems. frequency, and wavelength to solve problems.

5.5. Relate energy and amplitude. Relate energy and amplitude.

Properties of WavesProperties of Waves

A wave is a motion of disturbance.

medium—the material through which a disturbance travels.

mechanical wave—a wave that moves through a medium such as liquid, gas, or solid.


Wave Types

pulse wave—a single, nonperiodic disturbance.


Wave Types

periodic wave—a wave whose source is some form of periodic motion.

sine wave—a wave whose source vibrates with simple harmonic motion.

Properties of WavesProperties of WavesTypes of WavesTypes of Waves

transverse wave– a wave whose particles vibrate perpendicularly to the direction of wave motion.

crest—the highest point above the equilibrium position.

trough—the lowest point below the equilibrium position.

wavelength—the distance between two adjacent similar points of the wave, such as from crest to crest or trough to trough.

waveform—graphic representation of the shape of a wave that indicates its characteristics.

Anatomy of a T-waveAnatomy of a T-wave


longitudinal wave– a wave whose particles vibrate parallel to the direction of wave motion.


V = f *λV = wave speed (m/s), f = frequency (Hz), λ = wavelength (m)

Speed of WavesSpeed of Waves

Sound- usually between 330m/s and 345m/s Sound- usually between 330m/s and 345m/s in “air”. Depends on the gas it’s in. Ex: Pure in “air”. Depends on the gas it’s in. Ex: Pure Hydrogen= 1284m/s, Carbon dioxide- 259m/sHydrogen= 1284m/s, Carbon dioxide- 259m/s

Light- 3 x 10Light- 3 x 1088m/s, always. m/s, always.

Light from the stars Light from the stars

takes time to get to us. Seeing takes time to get to us. Seeing

things from a loooong time ago things from a loooong time ago

with the help of new telescopes.with the help of new telescopes.

Wave InteractionsWave InteractionsSection 12-4Section 12-4

superposition– the combination of two or more overlapping waves.

constructive interference—amplitude is the same sign, so they are added together to form a larger wave.

superposition principle– when 2+ waves travel through a medium, the resultant wave is the sum of the amplitudes of the individual waves at each point.

destructive interference—amplitudes are different signs, so they cancel either partly or all the way to form a smaller wave.

SuperpositionSuperposition

ReflectionReflection

reflection—the turning back of a wave at the surface of a substance.

At a free boundary, waves are reflected.

At a fixed boundary, waves are reflected and inverted.

http://phet.colorado.edu/sims/wave-on-a-string/wave-on-a-string_en.html

Standing WavesStanding Wavesstanding wave—a wave pattern that results when two waves of the same frequency, wavelength, and amplitude travel in opposite directions and interfere.

node—a point in a standing wave that always undergoes complete destructive interference and therefore is stationary.

antinode—a point in a standing wave halfway between two nodes, at which the largest amplitude occurs.

Standing WavesStanding Waves

11stst Harmonic Harmonic

22ndnd Harmonic Harmonic

33rdrd Harmonic Harmonic

44thth Harmonic Harmonic

55thth Harmonic Harmonic

Standing WavesStanding Waves

Use a wave game!Use a wave game!

http://phet.colorado.edu/en/simulation/http://phet.colorado.edu/en/simulation/fourierfourier

(Level 4 is best for this concept)(Level 4 is best for this concept)

And use:And use:http://phet.colorado.edu/en/simulation/soundhttp://phet.colorado.edu/en/simulation/sound

Sonic BoomSonic Boom

When a sound wave is being produced by When a sound wave is being produced by a moving object and that object is traveling a moving object and that object is traveling at the speed of sound…we will look more at the speed of sound…we will look more into this topic in chapter 13. into this topic in chapter 13.

http://upload.wikimedia.org/wikipedia/http://upload.wikimedia.org/wikipedia/commons/e/e4/commons/e/e4/Dopplereffectsourcemovingrightatmach1.4Dopplereffectsourcemovingrightatmach1.4.gif.gif

Hearing BeatsHearing Beats

When two sounds are close, but not the same When two sounds are close, but not the same frequency, you will hear beats being produced. A frequency, you will hear beats being produced. A keen ear can be used to tune instruments this keen ear can be used to tune instruments this way.way.

https://www.youtube.com/watch?v=V8W4Djz6jnY https://www.youtube.com/watch?v=V8W4Djz6jnY

Click the above link to observe this phenomenon.Click the above link to observe this phenomenon.

Measuring Simple Harmonic Motion amplitude—the maximum displacement from equilibrium. (how high or...

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