Photoelectric effect & wave-particle duality

Konichiwa!!!
Watakushi-wa Mary Ararcon (Alarcon), desu.

Yesterday (November 7), we did Young's Experiment Problems and "The Current Model of light: Wave- Particle Duality" . We've also tackled pages 22-26 on the green booklet.

If you guys missed yesterday's class, here are the solutions and answers on the experiment problems.......

first, here's the formula:

λ = (X) (d)

L

where:

λ = wavelength
X= distance between adjacent nodal lines

d= separation between slits

L= perpendicular distance from the slits to the screen.

1)

λ = ?

d= 0.0190mm/ 1.9x10 -5m

L= .600m

λ = (0.0211m) (1.9x10 -5m)

.600m

λ = 6.68x10 -10 m/ 668nm

2)

λ = ?

X= 13.2 mm/ 0.0132m

d= 1.90x10 -5 m

L= .600m

λ = (0.0132m) (1.90x10 -5m)

.600m

λ = 4.18x10 -7m/ 4118nm

3)

λ = 596nm/ 5.96x10 -4mm

X=?

d= 1.90x10 -5m/ 0.019mm

L= 600mm

X = (5.96x10 -4mm) ( 600mm)

0.019mm

X = 18.8mm

4)

λ = 632.8nm/6.328x10 -7m)

X= 65.5mm/0.0655m

d= ?

L= 1.000m

d= (6.328x10 -7m) (1.000m)

0.0655m

d=9.66x10 -6 m

5)

λ = ?

X= 55.8mm/0.0558m

d= 9.66x10 -6m

L=1.000m

λ = (0.0558m) (9.66x10 -6m)

1.000m

λ =539nm

6)

λ =542nm/ 5.42x10 -7m

X= 4.00cm/ .04m

d= ?

L= 1.20m

d= (5.42x10 -7m) (1.20m)

.04m

d=1.63x10 -5m

7)

λ = v/f

λ =343m/s

325Hz

λ = 1.055m

X= ?

d= 4.0m

L= 4.5m

X= (1.055m) (4.5m)

4.om

X=1.18m/1.2m

If you are having a trouble reading the duality thighy,, I'm sorry..

I'll just type it for you,,

Particle model:

*Rectilineat Propagation

*Reflection

*Dispersion

*Photoelectric Effect

Both:

*Reflection

*Rectilinear Propagation

*Dispersion

Wave Model:

*RectilinearPropogation

*Reflection

*Refraction

*Dispersion

*Diffraction

*Partial Reflection and Partial Refraction

haish... it's now 6 am and I'm soooooo tired... I still have work tomorrow.. :(

well,,, for the last part,, just read pages 22-26 (green booklet)

Oh,, by the way,, if I'm not mistaken,, Ms. K will not be there on Monday..

Answer the question sheet because we will go over it on Monday..

We also have a test on Thursday...

Okay?!

Ganbatte ne? (Come on)

Aja Aja Fighting!!!!

Yours truly,,

Pretty Mary

and the next scribe is Wonderbread.... I'm sorry,, i don't know who you are. It's just that,,, your code name is cute... So,,, Good Luck...

Today in the beginning of class we basically just reviewed the notes we were supposed to copy off the board in the last 2 days...(Particle and Wave Theory of Light) But Mrs. K wrote it in a "simpler" way on the smart board...Here they are:


PARTICLE THEORY OF LIGHT
Scientist composed: NEWTON
Property easily explained by Particle Theory: Rectilinear Propagation (Travels in straight lines)
Reflection: angle of incidence = angle of reflection
Refraction: Light travels faster in water than air. (INCORRECT!!!)
Diagram of refraction:(below)

Dispersion: All colours of light have the same frequency. Wavelength x Velocity factors are different in each colour. --Wavelength of red is Largest
--Wavelength of violet is Smallest
Partial Reflection/Refraction: "Theory of Fits" Newton thought this was a weak explanation. Diagram-->

Diffraction: Particles interfered with the edges of a barrier (VERY weak explanation)



WAVE THEORY OF LIGHT
Scientist composed: HUGGENS
Property easily explained by wave theory of light: Each point is a new source for a wavelet to be created.(connect the wavelets & get a new wavefront)
Diagram---->>>>
Reflection: Angle of incidence = Angle of reflection
Refraction: Light slows down when entering water. (FOUCAULT showed that this happened)


Dispersion: (diagram below) (INCORRECT!!!)






Partial Reflection/Refraction: The Wave Theory is better able to explain this phenomenon than the Particle Theory.
Diffraction: Wavelength of light is very small. (GRIMALDI showed evidence for this)


Finally, near the middle of class we watched a video on youtube titled "YOUNG'S EXPERIMENT" and recieved MORE homework.
Finish questions 1-15. OMIT #2
and for extra practice...
Young's experiment problems.

I'M TIRED NOW...BYE GUYS!

Wave Theory of Light

WEDNESDAY, NOVEMBER 5, 2008

Appendix 2.4: Chart for Evaluating the Models of Light

MODEL: WAVE

Phenomena: Rectilinear Propagation

Supporting Arguments: every point on a wavefront can be considered as a point source of tiny secondary wavelets the spread out in front of the wave at the same speed.

Counter-Arguments: Newton said the the wave theory adequately explain Rec. Prop since waves emitted from a point source spread out in all direction.

Phenomena: Reflection

Supporting Arguments: Light reflects from a surface and the angle of incident is the same/equal to the angle of reflection.

Counter-Arguments: None

Phenomena: Refraction

Supporting Arguments: when wavefront move into shallow water they refract so that angle of refraction is less than the angle of incidence

Counter-Arguments: None

Phenomena: Dispersion

Supporting Arguments: Color of light have the same frequency but different wavelength.

Counter-Arguments: None

Phenomena: Diffraction

Supporting Arguments: When a large wavelength passes through a small opening you get a large diffraction and the opposite occur with a small wavelength and a large opening, wavelength of light very small.

Counter-Arguments: Newton said that if light was a wave should bend a lot more than the scientist Grimaldi observed.

Phenomena: partial reflection/ Refraction

Supporting arguments: waves partially effect/refract when there is a change in velocity partial reflection is noticeable when there is an increase in velocity partial reflection occurs when there is decrease in velocity.

Counter-arguments: None

Phenomena: Speed of Light

Supporting arguments: Wave theory shows that light slows down is a more dense medium (Foucault)

THE NATURE OF LIGHT: PART 2

THE WAVE AND PARTICLE MODELS OF LIGHT PROBLEM

ANSWER QUESTION: 1,3 TO 12

NEXT SCRIBE IS PRETTY MARY!

11/03/08

Hey guys, it’s been awhile. (:

During this period we worked on two sheets, "appendix 2.4: Chart for evaluating the models of light" and "contributions to the determination of the speed of light". Unfortunately, because of the Boo@DMCI pep-rally last Friday, we are a class behind. Either way, we are encouraged to work harder! ;D

--------------
Answers for Appendix 2.4: Chart for evaluating the models of light:
Phenomena: Rectilinear Propagation
Supporting arguments:
~Sunlight passes through clouds making straight lines.
~Sharp objects are cast
Counter-Arguments:
~None.

Phenomena:Reflection
Supporting arguments:
~very hard spheres collide with very hard surfaces and bounce off the same angle.
Counter-Arguments:
~none.

Phenomena:Refraction
Supporting arguments:
~When a ball rolls down a slip and continues on to a lower slope, the accelerating force causes the ball to change direction; resulting in a refraction.
Counter-Arguments:
~Speed of light in H2O is less than the speed of light in air.

Phenomena:Dispersion
Supporting arguments:
~each particle of a spectrum has a different mass. Violet refracted more than blue, so violet has small mass.
Counter-Arguments:
~All particles have the same mass.

Phenomena:Diffraction
Supporting arguments:
~Newton felt that the beam bending outward form a slit resulted from the interactions and collision between the light particles at the edge of the slits.
Counter-Arguments:
~Grnaldi showed that a beam of light passing through a successive narrow slits produced on a screen, a band of light slightly larger than the width of the slits.

Phenomena:Partial reflection/refraction
Supporting arguments:
~Newton proposed the “theory of fits”. “Fit” for easy reflection
Counter-Arguments:
~How does a particle know about what is good “fit”?

Phenomena:Speed of light
Supporting arguments:
~Light moves quickly in a dense medium.
Counter-Arguments:
~The opposite is true, light moves slower in a dense medium.

---------------

As for the other sheet, Im not done that yet. you’re on your own, sorry!
Ohh our labs for “Newton’s particle model for the refraction of light” was due today too, and we got to know our term marks. So for those who weren't here his period, you didn’t miss out on much.
~mary lam

Next scribe is tan00!

Physics 10.30.08 (:

haah! My creative mind is sort of dead today so I couldn't come up with a better title. -_-" Anywho, today Ms. Kozoriz wasn't here for the first part as she had to attend a meeting so there was a sub today. My ultra short memory has caused me to forget her name xD (wow do I ever feel bad -_-;). I think it was like Ms.K-something xD .
*Edit:Mrs. Karras ->thanks Ms. K



Today we just did a lab. It was to test out Newton's Particle Model for the Refraction of Light.


The materials that we used are highly unlikely to be found in our houses (unless you have a spare ramp , a wedge, a steel ball and carbon paper laying around somewhere). I pretty sure everyone was in class today, except for maybe one person (who shall remain nameless xD) so you know what I'm talking about. Anyways, for those people who didn't hand in the lab yet, you can hand it in on Monday because we don't really have a Physics class tomorrow. We have some Halloween/ Pep Rally/ Challenge/ Boo in the School thing last period so yea.





What to Hand in:


-Two white papers w/the ball path on them


-Graph


-Table of Data


-Questions on the back of the lab sheet





In case you don't understand what I'm talking about the questions were:





1.Why must you be careful to start the ball from the same point on the launching ramp?





2. Can this change in direction of the ball be described by Snell's Law?





3. What does this particle model of light predict about the speed of light in water compared with its speed in air?





And for the graph, don't forget a title, and that you are using sin"theta"i/r not "theta" i/r.





So that's it! Haah! So much for revenge John! LOL! Should've picked a busier class ;). So yea I guess all that's left to do is choose the scribe for MONDAY! lol. Any of you not sitting around me, you're safe for now (:.


So here we go!

Omedetou gozaimasu (congratulations) meimei! You are Monday's scribe!

'Kay well that's it from me! Happy (advanced) Halloween everyone! Don't forget to dress up tomorrow!

Peace out! Later! Bye! Cya! Gnite!

-pj (:

AGAIN?!

Man, looks like I'm doing this thing again.

Well today, we read the pages 2 - 7. This was about different theories like wave theory, tactile theory, emisson theory and corpuscular (particle) theory. After we read about this stuff, (yeah read) we did a work sheet on who made the theory, when the theory was made and what the theory was about, on top of that we had to draw a picture of each theory.

TACTILE THEORY
-Created by Plato
-Created during early Greece
-Stated that light consisted of "streamers" or filaments that was emitted from the eye and when that light hit an object, you were able to see it

EMISSION THEORY
-Created by the Pythagoreans
-Created in early Greece
-Stated that objects sent out light beams and the light would richocet off objects and would enter the eye, thus making it visible

PARTICLE THEORY
-Created by Newton
-Created in the 17th century
-States that light consisted of particles that traveled in straight lines

WAVE THEORY
-Created by Empedocles
-Created in early Greece
-States that light travels in waves

LOL! EYE see U. Yeah, sorry, I'm bored.

I'm choosing the scribe totally NOT random. I choose jaaaayp for my revenge, muahhahahha.... ahem... that is all.