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Sunday, May 21, 2017

Video analysis and the mass of the moon

We will investigate physics through the use of video analysis. The reasons for doing this includes a primary one of using Logger Pro software, which the school has from the Vernier electronic sensors, to do a video analysis. I want you to realize you can take any YouTube video, or any video (or digital photo) you take with your phone, and analyze any type of motion in any event you capture! This is a powerful tool that we all have access to in this day and age, and allows us to do so many more analyses. And with high-speed video options that more phones are providing, such as 120 frames per second (fps), 240 fps, and even 480 fps, or digital cameras that now provide 1000 fps or more, we can use video analysis software to look at finer details of motion than we ever could before in a high school lab. Keep in mind that a normal video is around 30 fps.

Watch this video for getting an introduction to using Logger Pro for video analysis.

One thing I recommend is to download a free piece of software called Tracker on a home computer (cannot do this with the Chromebooks, unfortunately), so you have the chance to check out details if you ever get the urge. This is an introductory video for using Tracker.

All you need is a few seconds of video to get into an analysis. For today we have as a goal to figure out the mass of the moon, perhaps using the original video footage of the first men on the moon in 1969! All you need is a bit of projectile motion to figure out the acceleration due to gravity, and the fact that the radius of the moon is 1079 miles. Work with a partner, and keep in mind you need to Google some conversions and get the mass of the moon in kilograms based on data from the video.You can use any moon landing video you want, including the moon buggy, dropping a hammer and falcon feather, or any other that involves some gravitational action you can use to figure this out. Also come up with a percent error compared to an accepted value of the moon mass.

Note that to import a video clip into Logger Pro or Tracker, you need to have the video file. To get this from your phone, of course you would need to just upload the video to your computer and then import into the software. For a YouTube video, you can make a screencast video file of the YouTube video, and save it to your computer. A quick, easy way to do this is to use Screencast-o-matic. Just select the brief scene you need to do the analysis, and capture it with the screencast! Here's a how to video for making a Screencast-o-matic video, which I suggest saving to your desktop or to your student My Documents folder. You will be able to Insert this video file into Logger Pro.



                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Monday, May 15, 2017

Video on the human eye

One video on the details of our eyes is here, or click on the embedded video below. An alternative is here.

Saturday, April 29, 2017

Funding site for the Kranti School in India

We were so fortunate for many students to meet Robin Chaurasiya, who stopped by ETHS while in Chicago. Her work in Mumbai, India, at the Kranti School, has gained her international attention, including a Top 10 Finalist rating in the 2016 Global Teacher Prize! She works with girls who have either been in or whose mothers were in the sex trade.

What needs to be known is Robin's school is a NGO (Non-Government Organization), and every penny to run the school and pay for some of the girls to study abroad and go to college has to be raised - there is no tax money or fixed revenue for such a school. If there is any interest in making any donation, whether small or large, one can check it out at this site. Through this site, 100% of the donations go to Kranti!

Wednesday, April 26, 2017

EM Work

For review, let's go into the AP Multiple Choice folder on your chromebook, and try the 2015 test (if this link does not work, go to the AP Exams folder and then into the Mult Choice folder). Remember you need to be logged into your eths202.org account to access these folders. You'll need to scroll down in that file to get to the questions, and the answer key is towards the end of the file.

It is up to you if you want to start by yourself and then work with others on anything you missed, or if you want to talk through things with one or two others. If individually, also keep a sense of pace by timing yourself for some number of questions.

*The important thing is to find things that you have forgotten or have had some trouble with in the past. Turn in your answer sheet and score. Whatever time you have left, you can work on the review set from the other day. Come with questions Thursday!  😊

Wednesday, April 19, 2017

Visitor on Tuesday, April 25: Robin Chaurasiya

Check out a brief bio of Robin Chaurasiya, who will be in town and visiting ETHS on Tuesday, April 25, in room H322. Come by during lunch periods to meet her and hear some thoughts about what she does in India with her students. There is also a good video showing what the girls do in terms of performance at the Kranti School.

Tuesday, April 11, 2017

PhET simulation for EM induction

We will be trying the generator and transformer simulations for class. Check it out! The link is https://phet.colorado.edu/en/simulation/legacy/faraday.



Monday, April 10, 2017

Inductor Circuits!

We are moving into the final topic of high school physics: Inductors!

Check out a few videos if you need to review or double-check anything:

- series RL circuit
- Parallel RL circuit 
- LC circuit 

- Maxwell's displacement current, about how capacitors work and the final piece to Maxwell's equations
- Maxwell's equations (Mechanical Universe episode; good graphics of EM waves)