Medium II. Pulses and Waves medium – what a pulse or wave _________________________ __________ (The plural of medium is __________ .) propagates (moves) through media Medium pulse energy moves _______________ the source by the pulse or wave energy _____________ source disturbs the medium here away from wave Pulses and waves are caused by ____________________ and transmit ____________ (but NOT ____________) through the __________________ . vibrations energy mass medium

Examples of Waves (or Pulses) and their Media: – require a medium: _______________________ because the wave ____________________________ of the medium as it passes through it - ___________ propagate in a vacuum Sound solids, liquids or gases displaces the particles cannot ____________ waves: – ________________________ a medium - are composed of _______________________ fields - can propagate ___________________ as well as in solids, liquids and gases. Light do NOT require electromagnetic in a vacuum

single disturbance pulse - a __________________________ that propagates through a medium velocity v = ______________ of pulse A equilibrium ___________ position of' the particles in medium the maximum displacement amplitude A - _______________________________of the medium as the pulse or wave passes through it

wave - a ___________________________disturbance that periodic (regular) wave - a ___________________________disturbance that propagates through a medium crest (peak) v A A ________________ position of medium equilibrium trough Only ___________________ is usually shown. Unless otherwise stated, it is usually assumed that the wave ___________________________________________________ The diagram shows a __________________ at one time. part of the wave continues infinitely in both directions snapshot

A. The amplitude A of a wave determines how much _____________ it transmits. The energy transported is proportional to the ___________________ . energy square of A Amplitude: _______ _______ ________ Energy: _______ _______ ________ A 2A 4A 4E 16E E loudness Sound: Amplitude determines ______________ small A: ________   large A: _________ Light: Amplitude determines ________________ small A: ________   large A: _________ soft loud brightness dim bright

Ex: Radio waves and light are types of ___________________ radiation. One way that information can be sent by radio waves is by _____________________ (changing) the wave's ___________________ : This is called _____. Here is how it is done: electromagnetic modulating amplitude AM 1. This wave has the ___________________ info to be sent 2. This wave is called the ____________ carrier AM wave 3. This is the ___________ The ____________ wave's amplitude has been ______________ by wave 1. carrier modulated

B. The 3 basic types of waves: The medium v is ___ the wave v Ex: ____________________________ transverse medium v ┴ wave v light, S earthquake waves Displacement d _________________ of the medium as the wave moves to the right: _______ v wave neg. d x equilibrium pos. d Where is the displacement zero?

2. _________________ waves The medium v is ___ the wave v Ex: ___________________________ longitudinal || medium v sound, P earthquake waves wave v Displacement d _________________ of the medium as the wave moves to the right: _______ v wave pos. d neg. d Where is the displacement zero?

________________ waves: The medium v is __________________ to the wave v. Ex: ____________________________________ Combination both ┴ and|| water, some earthquake waves medium v wave v Because it is easier to visualize, both ___________________ and ____________________waves are drawn as if they were _________________ waves. longitudinal combination transverse

┴ A transverse pulse moving to the right: at rest particle ____________ at rest moving ____ up later max. _________displacement later down moving __________ later at rest ____________ later ┴ Note: particle of medium moves _____ to wave v

A transverse wave moving to the right: In which direction is the medium moving at points… 1 5 4 2 6 3 Imagine the wave at a slightly later time. Note: Top points 1 and 5 are moving __________ Bottom point 3 is moving _________ Points 2 and 6 are moving ___________ Point 4 is moving ____________. down up up down

A transverse wave moving to the left: In which direction is the medium moving at points… 1 5 4 2 6 3 Imagine the wave at a slightly later time. Note: Top points 1 and 5 are moving ___________. Bottom point 3 is moving __________ Points 2 and 6 are moving _________ Point 4 is moving __________. down up down up

l C. _______________ l (__________): the ______________ between two __________________ points on a wave that have the same: 1. _____________________________ , and 2. __________________________ . distance Wavelength lambda consecutive distance from equilibrium direction of motion v = ____ l x z d = ____ y _____________  same ______________ from equilibrium. Only __________  moving in the same ________________. x, y, z distance x and z direction

In sum, l is the distance between consecutive _________________on a wave. similar points l l/4 l l l l/2 l/4 l/2

Wavelengths are sometimes measured in terms of ________________ . In this case: ____ l = _________ angles 1 3600 2700 ¾ ½ 1800 900 ¼ These angles are sometimes called the ______________ or ____________________ of the wave. phase phase angle

Two points on a wave that are 1l (3600) apart or a multiple of 1l are said to be ____________________ in phase Two points on a wave that are (½)l (1800) apart or a multiple of (1/2)l are said to be __________________ ________________________ . completely out of phase Label points on the wave below that are in phase with point A. Then label the points that are completely out of phase with A. Repeat for point B. = in phase = out of phase B A