Upload
burnsjo
View
221
Download
0
Embed Size (px)
Citation preview
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
1/74
Physical ScienceCh. 10: Waves
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
2/74
A wave is a rhythmic disturbance which carriesenergy through space or matter.
Many waves, but not all, require a medium to movebetween points, these are called mechanicalwaves.
A medium is a material through which a wavetransfers energy.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
3/74
Which of the following would bemechanical waves?
Light ound
!ltraviolet "!.#.$ waves
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
4/74
%ypes of Waves
&ased on the way they move, there
are ' different types of waves(
). %ransverse Waves
'. *ompressional Waves
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
5/74
%ransverse Waves
+n a transverse wave, the waves mediummove perpendicular to the direction of the
wave. -. ocean waves, light waves
/or eample, as the wave moves left to right,the medium moves up and down.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
6/74
ay youre waters0iingdown at the la0e andyou wipe out. As youfloat in the water and awave goes by, whatdoes your body do asthe wave passes?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
7/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
8/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
9/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
10/74
Parts of a Transverse Wave
%here are 1 main parts to a transverse wave(
*rest2 the highest point on a transverse
wave
%rough2 the lowest point on a transverse
wave
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
11/74
Amplitude2 the distance from either the
crest or trough to the resting point of thewave
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
12/74
Wavelength2 distance from crest to crest
or trough to trough on a wave
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
13/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
14/74
Wave /requency
/requency is a property of a wave, not apart of one.
/requency is the number of waves whichpass a given point in ) second.
3ert4 "34$ is the + unit for frequency.
) 34 5 ) wave passing a given point in
) second
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
15/74
o if you6re sitting on a boatdoc0, and ) waves washes
up against the doc0 everysecond, then the wavefrequency is ) 34.
What if ' waves hit persecond?
What if ) waves washes pastevery ' seconds?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
16/74
When you tune in to a radio station, thenumbers on the dial represent the frequencythat a particular station is sending their signal
out at./M 7 M34 "megahert4$, 89.8 5 89,8::,::: 34
AM 7 ;34 "0ilohert4$,
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
17/74
Which band, AM or /M, usually has better
sound quality? Why do you thin0 this is so?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
18/74
%he period of a wave is the amount of time itta0es one wavelength to pass a stationary
point. %he wave below has a period of about' s.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
19/74
Compressional Waves
A compressional wave vibrates in thedirection that the wave is travelling. Thesewaves are also known as longitudinal waves.
Examples slink!" sound waves
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
20/74
%he ' main parts of a compressional wave are(A. *ompression2 area of higher density
within the wave&. =arefaction2 area of lower density
within the wave pg. '8
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
21/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
22/74
ound Wavesound Waves
ound waves are a type of compressional
wave which require a medium to travel.
ound waves travel at about >: mi@hr.
%his speed is effected slightly by the type
of medium, temperature of medium, and
elevation.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
23/74
When an obect such as a et travels at aspeed greater than >: mi@hr it is said tobe supersonic.
What happens when an obect travels atsupersonic speeds?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
24/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
25/74
%he %hrust* "supersonic car$ bro0e thesound barrier on land, going >.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
26/74
%he photo below shows the shoc0 waveproduced when the car bro0e the soundbarrier.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
27/74
A shoc0 wave is a rapid change in air pressurecaused by a strong disturbance. %he shoc0 wavemoves outward from the disturbance.
Large eplosions and sonic booms can producestrong shoc0 waves.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
28/74
%hin0 of a roc0 being thrown into a pondand producing outward ripples. A strong
disturbance can produce the same typeof ripples, only in the air.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
29/74
A boat moving though water can producewaves which are more bunched up in front of
the boat in the direction that it is moving. othere are more waves per second"frequency$ out in front of the boat.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
30/74
Let6s say that the boat travels fast enoughfor the waves being produced to start to
overlap each other, so that a stationarypoint "$ is hit by more than ) wave at atime.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
31/74
%his would cause that point to eperience
much more wave energy all at once.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
32/74
%his is fairly easy for the boat to accomplishsince all it would have to do is move faster thanthe waves, which travel relatively slowly.3owever, the same thing can happen in the airif the obect "a et$ can travel faster than thewaves in the air "sound waves$.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
33/74
When the tremendous amount of energyrequired for this to occur produces waves,
and these waves start overlapping andstri0ing a point several at a time, then a sonicboom is eperienced.
Cust li0e the boat produces continual waves
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
34/74
Cust li0e the boat produces continual waves,so does the et. o as long as it stays above>: mi@hr, a continual sonic boom will be
produced following along slightly behind theet.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
35/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
36/74
+f you are on the ground as the et goesover, you will here only a single boomthough, as the shoc0 wave moves pastyou following the et.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
37/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
38/74
3ow far away can a sonic boom be felt orheard?
What happens as the et drops bac0 below>: mi@hr?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
39/74
Wave speed is the rate at which a wave is
traveling, and is measured in m@s.
%he formula for wave speed is(
frequency "34$ wavelength "m$
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
40/74
+f a sound wave "DD m@s$ has a frequency
of 34, what is its wavelength?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
41/74
#elocity 5 /requency Wavelength
so
Wavelength 5 #elocity @ /requency
5 DD m@s @ 34
5 5 m
= fl i d = f i
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
42/74
=eflection and =efraction
=eflection is where a wave stri0es an obect and
bounces off. When a wave stri0es a flat reflective surface it will
reflect bac0 at the same angle that it struc0 the
surface at. %his is calledEEE
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
43/74
%he Law of =eflection
%he law of reflection states that the angleof incidence is equal to the angle of
reflection on a flat reflective surface.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
44/74
-amples of the Law of
=eflection(
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
45/74
3ow is the Law of =eflection used in lasersecurity systems?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
46/74
+n addition to reflection a wave caneperience refraction.
=efraction is the bending of a wave as itenters a different medium, due to achange in speed.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
47/74
&ecause of light refraction, a person bowfishing would not aim directly at the fish.
Where should they aim? 3mmmmEEE..
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
48/74
Fiffraction Fiffraction is the bending of a wave, around a
barrier.
-.( Light in the storage room partially illuminating the
classroom.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
49/74
ometimes ' or more waves may come incontact with each other and overlap to form a
new wave. %his is called interference
As these waves overlap, they can eithermultiply and enhance each other, or canceleach other out.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
50/74
*onstructive interference occurs when thecrests and troughs coincide and produce a
larger amplitude "greater overall combined energy$
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
51/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
52/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
53/74
-amples of constructive interference(
7 ' people trampolining at the same time
7 ' or more people singing together "in sync$
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
54/74
Festructive interference occurs when thecrests of one wave coincide with the troughs
of another, creating a smaller amplitude.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
55/74
- l
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
56/74
-amples(
2 ecessive echoing in a stadium or arena,
which distorts the G.A. system2 ' or more people singing together "out of
sync$
i d i h H i l A h ill f
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
57/74
ingers doing the Hational Anthem will often
wear earplugs because the strong echo
coming bac0 through the stadium caninterrupt their timing of the song.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
58/74
Many locations, such as auditoriums andmodern stadiums are specifically designed
to produce constructive interference.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
59/74
Waves created through and along thecrust of the earth by shifting or brea0ing
tectonic plates are called seismic waves.
%hese waves are comprised of
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
60/74
pboth transverse andcompressional waves, and can
create very damagingearthqua0es.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
61/74
%he an Andreas /aultline in *alifornia and the
Hew Madrid /ault in -Missouri are ' locationswhere plates come
together, and aretherefore more li0ely toslide or brea0.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
62/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
63/74
!nderwater earthqua0es can oftenproduce tsunamis, giant ocean waves.
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
64/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
65/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
66/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
67/74
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
68/74
When Foug was driving
from ;ansas *ity to
Fenver, he crossed overfrom the central time 4one
to the mountain time
4one. When he arrivedhe went to change the
time on his cell phone,
but found that it had
already changed. 3ow
did that happen?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
69/74
As *arl was driving
through the B4ar0s, hefound that he could not
tune into a radio station
and maintain a signal,even for stations nearby.
Why was this?
%he outh American
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
70/74
%he outh Americanarcher fish shoots astream of water
which 0noc0sunsuspecting preydown into the waterwhere they areeaten. Would thefish in the pictureneed to aim higher
or lower than whereit perceives the bugto be?
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
71/74
A : caliber sniper rifle fires a proectile at
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
72/74
A .: caliber sniper rifle fires a proectile at),::' m@s. +f the rifle is fired at a target andthe bullet ta0es ' seconds to reach thetarget, how long after the bullet stri0es will itta0e before the crac0 of the gun is heard?"speed of sound 5 DD1 m@s$
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
73/74
&ecause sound travels at >: mi@hr, you can
calculate that it will travel about ) mile in
seconds.
) hr. 5 D,:@D,
7/26/2019 Physical Science Chapter 10 (New Book) .ppt
74/74
p p gthe sound barrier, producing a sonic boom.+f you hear the boom ) minute after the et
passed by, how high was the et flying?