Notes:_____
Chapter 11 Notes
Date: _______
11.1: Waves
Waves are disturbances that transmit ________________ either through a substance,
called a ________________, or through empty space ( a ________________). Any wave that
requires a _______________ is called a _______________________ wave. This includes almost
every type of wave except for ____________________________ (
) waves such as __________
or __________. ______ waves are produced by disturbances in electric and magnetic fields
(hence, EM).
____________________ often cause waves. For example when a vocal chord (or a guitar
string) is vibrating air around that object begins to move in response to the vibration;
those vibrations are carried outward in all directions through the medium. As the energy
moves outward it gets spread over a larger area (called the ______ _________) and lessens
in intensity (like a balloon’s thickness gets smaller as you inflate it). As the particles
move outward they transfer their energy through collisions. These collisions cause the
energy to move outward in approximately straight lines.
There are two different ways the particles in a medium can vibrate: ______________ or
_____________________.
___________________ waves move up & down as the energy moves through the medium so
the particles of the medium move ____________________ to the energy:
_______________________________________________________
examples of ____________________ waves include ____________ and ______________________
During _____________________ waves the particles of the medium move parallel to the
direction of the wave’s energy:
_______________________________________________________
Examples of _____________________ waves include _________ and ________________________.
_________________ waves occur at the boundary between two mediums (like water & air)
and are a combination of transverse and longitudinal waves. The particles at the surface
simultaneously move up & down and side-to-side making small circles of motion:
11.2 Wave Characteristics
Transverse waves appear as _________ waves:
_________________________________________________________ < --________ _______________
The __________ is the highest point of the wave; the _____________ is the lowest; the
_________________ is the distance between _______ _______________ and either the crest or
trough (or 1/2 the distance between crest and trough). The __________________ (λ, lambda)
is the distance between any two identical points along the wave (crest to crest or trough
to trough, for example).
The _____________ (
) is the time required for one full wave to pass a point--it is
measured in _____________. The _________________ (
is the reciprocal of the ______________ ( so
) is how often a wave passes by--it
= –—– ). So, if the period is 10.0 seconds
the frequency is ________ or __________. [ or ________ which is also _____________ (
Example:
_____________________________________________
since T = ______ f = ________ = _________
)]
Longitudinal waves:
____________________________________________________
The __________________ is the region where the wave is spread out; a __________________ is
where the wave is squeezed together. The ________________ is 1/2 the size of the
______________.
Figure 11-12 and Table 11-1 (both on p. 368) and the next page) show the range of visible
light and the entire EM spectrum. Note: _______ frequencies = _________ wavelengths and
the ___________ the frequency the ___________ the energy. Visible light (ROYGBIV) has
wavelengths between ______ nm (
) to _______ nm (
). Note 1 nm = _________
m.
Speed of waves.
Recall that velocity equals distance ÷ time so:
Example 1:
What is the velocity of a 1.0 m wave if its period is 4.0 seconds?
Example 2:
What is the wavelength if a wave traveling at 15.0 m/s has a frequency of 5 Hz?
The Visible Light Spectrum
Seismic (Earthquake) waves are energy comprised of both longitudinal waves (called
______________) and transverse waves (called _______________). P-waves are also called
______________ waves because they travel faster than s-waves (____ km/s vs. ____ km/s)
so they arrive first. P-waves travel through ____________________________ but s-waves can
only travel through ___________. Additionally _______________ waves occur: these are
called ________________ and are caused by the shaking of the Earth like a giant bell.
The above diagram is how scientists know the interior of the Earth without actually
drilling that deep. The size and composition of each layer is very precisely measured.
11.3 Wave Interactions
There are 5 common properties of waves:
1) Rectilinear (straight-line) propagation--
2) Reflection--
Laws of Reflection
3) Refraction--
(cat’s
view)
4) Diffraction
5) Interference
(fish’s
view)