Why building housing on Peoples’ Park is not, and will never be, a good idea.

Photo of People's Park
People’s Park stands at 2.8 acres. (UC Berkeley photo by Brittany Hosea-Small, photo links to website.)

I suspect most Berkeley residents don’t go to People’s Park very often, if at all. Even as one who grew up in Berkeley during ‘the sixties,’ I never set foot in the Park until I was a student at Cal in the late ’70’s. I suspect most people view People’s Park as a destination that they don’t find attractive. Sure, there is a reasonable collection of us who have given sweat and tears, and even blood, to maintain this land as a park, whether that be in the ’60’s as the park was created/reborn, or during the decades since, when the University attempted several times to fundamentally alter the use of the Park. But it is likely that the majority of folks in Berkeley have no strong connection to the Park.

So now, as its 50th anniversary approaches, I suspect that most folks in Berkeley see People’s Park as an ‘attractive nuisance’ at best, and perhaps a ‘dangerous eyesore’ at worst. So the current proposalthat includes 700-1,000 student beds, 75-110 ‘supportive housing’ beds, and ‘park/open space’ with “… an important element … design that will commemorate, honor and celebrate the history and the significance of People’s Park”—will likely be received by most folks as a step forward. I would like to offer, however, an alternative, long-term view of this proposal. Continue reading “Why building housing on Peoples’ Park is not, and will never be, a good idea.”

Solving ‘roller coaster’ energy problems

Step-by-step instructions.

Try to complete each section on your own before you move to the next image. Each slide shows the answer to the preceding question.

1. First, examine the problem and determine the energy storage types involved.

Slide showing the roller coasterThis problem consists of a roller coaster which has a chain that pulls the car to the top of the first hill. The problem defines the system as frictionless (μ = 0), and insignificant air resistance.
Before you go on, define the system, then draw axes for your energy diagrams at each point with a letter (don’t worry about the number of blocks of each energy storage yet).

2. Determine where energy must be added or removed from the system.

Slide showing energy storage types on axes.

How did the car get up the first hill? How does the car come to a stop at the end?

Before you go on, add working arrows pointing into or out of the system.

3. slide showing workAdd blocks to represent units of energy on each graph.

Remember that at this point, we are not worried about the exact amount of energy stored in each type; we just need to make sure that Ei + W − Ediss = Ef for each transaction.

Before you go on, add your energy blocks to each graph.

4. Look at the problem and determine which points in time can be used to answer the question.

slide showing energy storage distribution

Here is the next question, and the energy storage diagrams from the two points of concern.

slide showing

Since this question asks about the speed at Point D, we can select that point and C, since we know both the speed and height at C.

Before you go on, write out the balanced energy equation for Points C and D.

5. Rearrange your equations to solve for unknown, then enter your values and solve.

Before you go on, rearrange the equation to solve for vD, then plug in your numbers and solve.

6. Your done!

Before you go on, check to make sure your answer is reasonable.

Since the car started at 3 m/s at the top of the hill, 24.4 m/s seems ‘reasonable’ for the bottom of the hill. (Remember the shortcut that m/s*2≈MPH, so 24.4*2 ≈48.8 MPH, a nice, fast roller coaster.)

7. Here’s another problem involving the loop.

Try it out using the above steps (but remember, since it involves centripetal forces, you will need to use Fc = (mv2)/r = Fnet.


Before you scroll down,draw a force diagram for the car and an energy equation for two locations.

8. Expand all your equations and rearrange them to solve for the unknown.

9. Combine your energy and force equations

10. Solve!

11. You are done.

Once again, does this answer seem correct? Compare it to the normal force of the cart just resting on the ground.

How helpful was this?

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Swords to Plowshares at the national weapons labs: Late 70’s/early 80’s

Poster from July 1979 protest at University of California Regents meeting
Poster from July 1979 protest at University of California Regents meeting

In the late 1970’s/early 1980’s, I was part of a movement to convert the nation’s premier nuclear weapons developing labs (Lawrence Livermore in California, and Los Alamos in New Mexico) from labs that primarily focused on research in nuclear weapons to ones that focused on human needs.

The UC Nuclear Weapons Labs Conversion Project (UCNWLCP) was born as a coalition of Berkeley Students for Peace, the Ecumenical Peace Institute/CALC, and the War Resisters League West.  Livermore and Los Alamos were managed by the University of California (and still are). Our goal was to use the university’s management influence to press for “swords to plowshares.” We lead teach-ins, held direct actions, brought petitions to the Regents, and build coalitions with University and lab employees and scientists. Continue reading “Swords to Plowshares at the national weapons labs: Late 70’s/early 80’s”

Beach cleanup daily — without leaving your home

photo of trash in garden

Map showing CA waterway cleanup locationsEach third Saturday in September in California, the California Coastal Cleanup Day gathers thousands of people to help clean tons of trash from our beaches and waterways. The 2017 event occurred on September 16th.

If you missed September 16th, and can’t wait until next year, you can start today in without leaving your own property. Continue reading “Beach cleanup daily — without leaving your home”

Back to School Night – Menlo-Atherton HS, 2017

image of back to school night home pageOK, maybe I’m in the minority, but I really like Back to School Nights. I appreciate the parents taking time out of their busy lives to come in and get a sense of who is teaching their students.

Tonight was no different. Great parents, lots of appreciation expressed, and a few good questions thrown in (not much time in ten minutes to ask questions).

Unfortunately, as usual, the higher academic classes have higher turnout of parents. Why? I can speculate about amount of free time, ability to get off work early, etc. But in the end, I don’t think it’s anyone’s fault (I suspect that all parents want their kids to be successful in school), it’s just a reality.

Thanks to all the parents who did make it out (and thanks to all those who didn’t for trusting your students in my care).

Here are handouts of the slides I used:

 

How I generate science tutorial videos

image of an old film camera

image of listing of some of the videos I have on YouTubeI have been making many video tutorials for my science classes in the last few years, and some folks have asked how I  create them. I have gone through a process of  changes, so I thought I’d present the options I have used to create them.

After you read this, please leave any comments or questions in the Comment section at the bottom of the page. Continue reading “How I generate science tutorial videos”

Videos of building molecules, and showing chemical reactions, with candy and toothpicks

Image of Ethyl acetate glowing for cover

Following are a couple of videos to provide students with examples of how to solve a couple of tasks in chemistry.

Building chloromethane

Using Lewis dot structures to determine how a molecule will bond.

Ester synthesis from acetic acid and ethanol

The exact mechanism is more complicated than shown here, but the basic atom movement between reactants and products is accurate.

Modeling Instruction and NGSS: Energy as a Crosscutting Concept

NGSS 3D learning logo

At the January 2017 Lasallian Symposium at St. Mary’s College in Moraga, CA, I presented a short talk describing how Modeling Instruction uses energy as a Crosscutting Concept for implementing the Next Generation Science Standards. You can download a copy of the slides from my talk here.

Video (without narration)

Extra time on quizzes: Why you need individual work

photo of students being loud

Today was a great day.

My students had a short quiz, and I wanted to make sure they all had plenty of time to complete it. I thought it would take them about 20 minutes to finish it (most finished in 15-20 minutes), but wanted to allow plenty of time for students who require ‘extra time’ (whether LD diagnosed and on an IEP or not diagnosed). I set the timer for 30 minutes, and, since my school is a BYOD school (every student has a computer of some kind), I created an assignment on our learning management system (Schoology, see screenshot below).

Before the quiz, I spoke with my students about what I was doing, sharing my concern with being able to provide in-class time for students who need extra time, but not having those who finish quickly sit around waiting for others to finish. Most of them understood and thought this was a good idea.

And, when the moment of truth arrived, when most were done with the quiz, the class was still pretty quiet. No students whispering to each other (well, only occasionally), and most working on their chemistry.

Of course, I should do this all the time, but sometimes I forget. Today was an example of the importance of a complete lesson plan.

Screenshot  of my Schoology assignment

Image of Schoology page with assignment

Classroom photo image source.

The periodic spiral of the elements

traditional periodic table

In working with my students’ perceptions of the periodic table, I wrapped a periodic table around a roll of paper towels. My attempt was to get them to realize that the Alkali metals are actually right next to the Noble gasses. I wasn’t sure if it was working, but in our review leading up to the finals one girl mentioned that it was a spiral–so I guess it’s helping some students.

Others have done this in a flat design (e.g. see P. Fraundorf’s page showing many great designs), but I wanted to show the idea in 3D.

Below is a video showing a periodic table spinning around on a turntable. I recommend downloading the video and using VLC Media Player, Quicktime, or some other viewer that allows you to scroll the video back and forth.

The table I used comes from ptable.com, a great resource for online and printable periodic tables.

Here are a couple other 3D ‘tables’ that email list folks have let me know about: