Light Test Review Materials

Review Questions

Review Questions Key

Finally about 20% of the unit test will be about how scientists understand the nature of light.  We have not only investigated the particle and wave models we have looked at how experiments have caused our understanding of light to switch models.  This document summarizes some of the major observations and experiments we have considered and identifies which model they support more strongly.

More review answers are here Snell's Law Worksheet - Key

Summary of Light Experiments

Here's a link to a summary of the experiments we've talked about in class.

https://docs.google.com/document/d/1k7Nxuhm3AfzBQbOk58xCCizxZB0Yy8fuuRH6ySFF6T0/edit

How to Stay Caught Up in Class Despite Field Trips, Testing and Other Disruptions

Of course the best thing is to be in class.  None of these alternatives will have all of the nuances of my presentation, but they are good, and doing some of these outside of class will make it easier to make sense of what is going on when you come back to class.

These descriptions are labeled by the dates that periods 2,3 and 4 will cover this material.  Period 6 always hits it the next day.

Wed 3/9 - Converging lens activity and notes on principle rays and ray diagrams
Something similar online :  Most of lesson 5 here  http://www.physicsclassroom.com/class/refrn  Also the interactive that is linked to throughout the lessons will be good.

Friday 3/11 - More practice with converging lenses, ray diagrams, and the lensmaker's equation.  Also introduce diverging lenses.
Something similar online:  More of lesson 5 here:  http://www.physicsclassroom.com/class/refrn  and the interactive

Tuesday 3/13 (ACT day)  - More details about the wave model - interference, the 2 slit experiment, and the electro magnetic spectrum
Something similar online:  http://www.physicsclassroom.com/class/light lessons 1 a,b,c 2a and 3a

Thursday 3/15 - Review, the photoelectric effect, Compton x-ray scattering

Online possibilities: http://www.youtube.com/watch?v=4uBekxM4vEc

http://phet.colorado.edu/en/simulation/photoelectric

Particle Model for Light

Here is the prompt for the lab report.

Write a  two paragraph conclusion for the lab.  It should focus on the plausibility of light being made of particles and show logical reasoning based on the results of our lab.  You may want to start it with one of the sentences below.

The results of this lab allow me to state that there is evidence that light could be a particle, because…

The results of this lab allow me to state that there is evidence that light probably isn’t a particle, because…

The results of this lab do not allow me to state that there is evidence that light is a particle or isn’t a particle, because… In order to have had more useful data, I would have needed to …

The second paragraph should propose a further test you could perform on either particles or light to confirm or deny the possibility that light is made of speeding “photon” particles.  It would be great if it was an experiment that you could actually perform in the classroom, but it is probably more realistic that it is simply an experiment that people could perform assuming that they had better equipment than we do.

This is not a research project.  I don't expect a historical or established experiment.  In class we listed a number of assumptions necessary to make a particle model for light workable.  Some of these were assumptions about light.  Some were assumptions about the necessary particles.  Focus on one of these assumptions and imagine/invent a test that probes its validity. 

In addition to the conclusion, please include a screen shot of your data table and graph.