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In the last of the Physics Project Lab blog posts, Paul Gluck, co-author of Physics Project Lab, describes how to create and investigate the domino effect…

Many dominoes may be stacked in a row separated by a fixed distance, in all sorts of interesting formations. A slight push to the first domino in the row results in the falling of the whole stack. This is the domino effect, a term also used in figuratively in a political context.

You can use this amusing phenomenon to carry out a little project in physics. Instead of dominoes it’s preferable to use units that are uniformly smooth on both sides, say for example building blocks for kids. Chuildren’s building blocks usually come in sets of 100, 200 or 280 blocks.

The blocks are stacked in a perfect straight line, absolutely uniformly spaced. To ensure this, lay them along the extended metal strip of a builder’s ruler several meters long, fixed at both ends. A non polished wooden floor is a suitable surface, since its roughness is enough to prevent any sliding of the blocks while falling.

What is interesting to measure and correlate in your experimentation? You want to measure the speed of the pulse when the first block is given a reproducibly slight push. In other words, you must measure the total length of the stack, as well as the time between the beginning of the fall of the first block and the fall of the last one. The speed will then be the total distance divided by the time elapsed.

There are several questions you can ask and investigate. First, how does the spacing between the blocks affect the pulse speed? Second, for the same spacing, how do the pulse speeds compare between two cases: the first, with the regular blocks, and the second when you double the height of each block (by sticking two blocks on top of each other to form a single block)? Third, for large numbers of units N in the stack, does the speed depend on the number of units (say when N = 100 and when N = 200)? Finally, does the speed vary for small numbers of units in the stack, say for values between 5 and 15?

For fair comparison between the various cases, you must devise a way to give the slight initial push reproducibly. One way you can arrange this is by releasing a pendulum above the first block and releasing it from a fixed distance so that at the end of its swing the bob just touches the first block, causing it to fall.

For time measurements you need a stopwatch. Be aware that you have a reaction time between when you perceive any event and the pressing of the stopwatch – this can be anything from 0.1 to 0.3 seconds. So repeat each measurement a number of times and take the average. If you have access to two photogates in a physics lab, you can devise a more accurate way of measuring the pulse speed. Actuate the first one by the beginning of the fall of the first block, the second one by the fall of the last one. Couple the two photogates by a circuit that triggers measuring the time when the first brick starts to fall and stops measuring it when the second block falls.  You can also video the whole event and analyze the clip frame-by-frame to calculate times.

Happy tinkering!

We hope you have enjoyed the Physics Project Lab series. Have you tried this experiment or any of the other experiments at home? Tell us how it went to get the chance to win a free copy of ‘Physics Project Lab’. We’ll pick our favourite descriptions on 9th January.

The post Physics Project Lab: How to create the domino effect appeared first on OUPblog.

        

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I'm posting some of my older comics here as I catalog and tag them in prep for a print book compilation:

I was thrilled when my copy of IRA's The Reading Teacher came in the mail yesterday. If any of you are members of the International Reading Association, this journal is one of the best in terms of practical ideas.

This month Tim Rasinski (as he does so often) pairs with a classroom teacher. This time the two discuss how reader's theater can create an academic pathway to grow students' fluency. I hope that those of you with experience with reader's theater review this article's abstract as well as the article itself if possible. On the online version, there is even an idea for using Jan Brett's book Hedgie's Surprise in a reader's theater environment from Read Write Think. If you have not used reader's theater in your classroom, now is a great time to try it, especially with the detailed approach outlined. Tim's website also provides a great list of sources for reader's theater scripts. You can even have your students create their own as part of a writer's workshop or groupwriting experience.

One point of the referenced article is particularly important in today's classroom with an increased focus on fluency. The purpose of improving fluency is increased comprehension. I fear that in the past few years, many schools have swung the pendulum too far in the direction of focusing purely on speed and the result, as Tim and Chase talk about in this article, is children that can read like a house afire but have little understanding of what the meaning behind the text is. That can be terribly damaging to their ability to read increasingly complex text as they move forward in their schooling.

I saw this first hand as I conducted a research study on fluency and the influence of family reading on first graders' growing fluency. In a study conducted in schools in GA, AL, TX and TN, about 80% of the students we asked to read a leveled piece which included inference could not identify what the children in the story were doing (building a snowman). Many students immediately upon finishing the one minute reading (timed so we evaluate all the students within a reasonable time) asked, "how many words did I read?". It seemed they had nearly been "programmed" to ask that, even when there was no direct evidence that this is what our assessment was attending to. In fact, I recommended this response to our evaluators who heard that comment: "I wasn't paying any attention to that; I wanted to listen and see if you sounded like you were talking when you were reading and whether you understand what the story was about." Although this was not the focus on the study, it was indeed a wakeup call.

Educators must be very careful as we work with students to improve their fluency that we do not minimize or sacrifice expressiveness, pacing, automaticity in word recognition, and decoding. Worst still, if speed is our primary focus, children get the mistaken idea that fast word calling is reading. That is simply not what makes a good reader. Whether we are working with beginning readers in kindergarten or first grade, or older students still struggling with reading, we must be sure that we are sending the messages that fluency is a tool, that reading is squeezing the juice of meaning out of text. If we do not send that message loud and clear, we may see children benchmark on fluency assessments but their comprehension (tested more frequently that speed of reading and much more important) will suffer.

Certainly we want our young and maturing readers to be fluent, but we also want them to be able to think deeply and widely, analyzing and evaluating what they read, rather than simply regurgitating facts. That takes excellent, engaged teaching, giving some time to fluency, but always going back to the focus and purpose of reading, to gain meaning from that text.

I'd love to hear about your experiences with reader's theater and how you are using it in your classroom. How are you putting fluency in its correct perspective with your students?

The world itself has become hectic and life a fast-forward motion picture.  Wherever one goes, everything must be done speedily.  This is because nowadays, almost in all families, both parents go to work, departing early and arriving late.  The indoors work is thus kept pending.  Beforehand, the speed of life was not so emphasized upon.  Only the husband was the bread-winner and so the housewife had all the time to cook, clean and complete the household chores.  Today, the parents, after a hard day’s work, must speed up and prepare something to eat for their children.  People, therefore, have to follow the new trend and adjust to a new lifestyle.

Image via Wikipedia

The on-the-move lifestyle includes the eating of fast food among others.  But even if “fast food” as we call it, people do not have time to eat a rounder properly; they either gulp it behind the driving wheel or eat it watching the television at the same time.  To speed themselves up and save time, people make use of sophisticated machines such as microwaves to cook food quickly, portable computers to complete office work….  After a speedy week, to supposedly relax themselves, people listen to music now – quick, hasty music.  It is the hard rock and technos.  This music is a great contrast to the old ones that were the real relaxing music.

These small factors contribute to big inventions, speeding the transport rate.  Long ago, there were ox carts and slow trains as means of transport.  With the evolution of science and technology and due to the speed revolution, buses, cars, motorcycles, aeroplanes as well as super-jet trains travelling at two hundred kilometres per hour were introduced.  Their need of fast transport then was satisfied.  As their burden of work grew heavier, the need of a quick means of communication was also felt.

Scientists and inventors put their heads together.  To support the level of speed of life and promote development, they abolished the hand-over of letters on horse-backs and established the links between one place and the whole world.  Speed developed the fax, email methods.  Through speed, the distance between the countries of the world is now lessened and so this helps the economic development of countries.

Speed may prove to be dangerous also.  The speed of a car, an aeroplane, a ship can endanger the lives of many people, if not properly controlled.  Cases of accidents where people had died are numerous.  For instance, the well-known ship “Titanic” sank as a result of sailing at full speed and thus inevitably crash into an iceberg.  How rightly has one stated that “haste makes waste”.

Image via Wikipedia

An old Christmas card design... Happy Haul-idays everyone!

© 2003 Barry/Right-Hemisphere Laboratory

I'm not sure a balloon is fast enough to get Santa to all his destinations. Reindeer might be speedier! Well, I did this for IF: Balloon this week, but I figured I could make it work here too.

And since we've had the Speed challenge for a while on Monday Artday, I figured some of you might want another challenge, so stop by my blog and enter our holiday card challenge...!

I'm not sure a balloon is fast enough to get Santa to all his destinations. Reindeer might be speedier! Well, I did this for IF: Balloon this week, but I figured I could make it work here too.

And since we've had the Speed challenge for a while on Monday Artday, I figured some of you might want another challenge, so stop by my blog and enter our holiday card challenge...!

Not quite speed, but pretty close.

Cover illustration for a story appearing in Westword magazine; about a guy who is a connoisseur, and reviewer of energy drinks.

© 2006 Barry/Right-Hemisphere Laboratory

        race against the wind!

This is my first post to monday artday.

3 youngsters racing in the bike with the wind against them and enjoying it .

I had done this illustration for printing on t.shirts.

This seemed apt for the title SPEED and so i have posted it here.

A future Hotrod Monster takes his little red wagon for a spin... speed bumps beware!

One of my biggest influences, and favorite things to draw, as a kid, were the hotrod monsters from the model kits, and bubblegum cards.

© 2008 Barry/Right-Hemisphere Laboratory

This week's challenge is:

SPEED!

Illustrate your version of "speed" in your style.

Because this is posted on a Thursday, you have until next Sunday (November 16th) to complete this challenge.

A note to my Monday Artday friends:

I'm sorry I was so remiss in getting judging, challenges, and join requests going in the last couple of weeks. I've been struggling with illness. I am going through a series of tests (blood tests, CAT scans, etc.) and I will let you know what the results are in a week. Thank you for your patience. - Mike

Something done to add drama to the portfolio:

Enjoy the Day,
Chris
chris-whetzel.com

We've been hard at work for the last several weeks improving the software that powers JacketFlap. I don't know about you, but for me, the speed increase is incredible! Pages that took 10 - 20 seconds to load last week now load in less than a second. We have a bunch of new features that we'll be releasing shortly, but we want to be sure the overall site is as fast as possible first. Please leave a comment here if you run into a slow-loading pages or other problems, and we'll get them fixed ASAP.

Thanks!
Tracy