Exam (elaborations)
PHYS 1260 Exam 4/50 Questions with Answers
- Course
- Institution
PHYS 1260 Exam 4/50 Questions with Answers
[Show more]
Content preview
PHYS 1260 Exam 4/50Questions with Answers
Superposition and Interference - -- same wave + same wave =
reinforcement
- two opposite waves = cancellation
- two similar waves = partial cancellation
- interference patterns of overlapping waves from 2 vibrating sources
- interference pattern = caused by interference b/w a pair of waves
- constructive interference produces bright region where waves reinforce
each other (waves arriving in phase)
- destructive interference produces dark region where waves cancel each
other (waves arriving half a wavelength out of phase)
- a monochromatic light into double slits produces an interference pattern
- the phenomenon of interference occurs for = sound waves + light waves --
> interference is the property that characterizes waves in general
-Superposition and Interference part 2 - -- single-color thin-film interference
= reflection from the upper and lower surfaces of a wedge of air b/w 2 glass
plates
- interference colors by reflection from thin films = the thin film of gasoline is
just the right thickness to result in the destructive interference of blue light
- diffraction grating = composed of a large number of close, equally spaced
slits for analyzing light source; produced by spectrometers that disperse
white light into colors
- if the thin film of gasoline was a bit thinner, the wavelength to be canceled
would be = shorter than that of blue
- if violet light were canceled by the double reflection of sunlight from
gasoline on a wet surface, the resulting color would likely be = orange -->
orange is the complementary color of violet
- if you see the color blue reflected in the interference from gasoline on
water, and you lower your head so a greater angle from the normal results,
you'll likely see a color having a wavelength = shorter than that of blue -->
the path through the gasoline would be longer, and a longer wavelength
would be canceled; the result of a long wave being canceled is a shorter
wave
-superposition and interference part 3 - -interference colors = that colors
are subtractive primaries = magnetas, yellows, and cyans
-double-slit experiment - -- monochromatic light passing through 2 slits, a,
forms an interference pattern, b, shown graphically in c
, - suppose we dim our light source so that, in effect, only 1 photon at a time
reaches the barrier w/ the thin slits
- if film behind the barrier is exposed to the light for a very short time, the
film gets exposed = each spot represents the place where the film has been
exposed by a photon; if the light is allowed to expose the film for a longer
time, a pattern of fringes begins to emerge
- if we cover one slit so that photons striking the photographic film can pass
only through a single slit, the tiny spots on the film accumulate to form a
single-slit diffraction pattern; we find that photons hit the film at places they
would not hit if both slits were open
-how do photons traveling through one slit "know" that the other slit is open
and avoid certain regions, proceeding only to areas that will ultimately fill to
form an interference pattern? - -- each single photon has wave properties as
well as particle properties
- the photon displays different aspects at different time
- a photon behaves as a particle when it is being emitted by an atom or
absorbed by photographic film or other detectors, and behaves as a wave in
traveling from a source to the place where it is detected
- so the photon strikes the film as a particle but travels to its position as a
wave that interferes constructively
-motion is relative - -- the place from which motion is observed and
measured is a *frame of reference*
- *an object may have different velocities* relative to different frames of
reference
- to measure the spd of an object, we first choose a frame of reference and
pretend that we are in that frame of reference standing still = then we
measure the spd w/ which the object moves relative to us - that is, relative to
the frame of reference
-michelson interferometer - -- a beam of light from a monochromatic source
was separated into 2 beams w/ paths at right angles to each other; these
were reflected and recombined to show whether there was any difference in
avg spd over the 2 back-and-forth paths
- the interferometer was set w/ one path parallel to the motion of earth in its
orbit
- either michelson or morley carefully watched for any changes in avg spd as
the apparatus was rotated to put the other path parallel to the motion of
earth
- but no changes were observed
-postulates of special theory of relativity - -- all laws of nature are the same
in all uniformly moving frames of reference
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Nursephil2023. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
80796 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now