VIP’s September 2013 E-mail Newsletter |

Website: http://vip.vast.org

President: Timothy Couillard

History of VIP |

-Tony and Andy

The Virginia Instructors of Physics was formed in 1988. Originally Ron Revere wanted to take his students to an amusement park to DO physics. His administration said he would need a letter supporting this trip as a learning activity. Ron got a letter of endorsement from the State’s superintendent of education, Joe Exline. Then he saw a bigger purpose of eliminating the isolation so many physics teachers felt because they were the only physics teacher in the building. James Madison University hosted a meeting inviting all physics to attend and get a free demo manual. (This was all before teachers had e-mail.) Out of that meeting in 1988 the Virginia Instructors of Physics, VIP, a less than non-profit group of physics teachers. VIP started and the physics day activities at King’s Dominion -until Paramount bought King’s Dominion. We even wrote a book about roller coaster physics and put it on our web site.

Since then VIP has led the way with handing our e-mail addresses to every physics teacher for free. You could connect using your telephone from home! VIP put out a physics newsletter about once every 2 months, then once every 4 months and had meetings at various universities twice a year. Currently the University of Virginia’s physics department, prints, stuffs, and mails a hardcopy of our annual newsletter to the over 200 teachers on our address list. We are affiliated with VAST, the Virginia Association of Science Teachers, and support several presentations every year at the VAST Professional Development Institute for physics and physical science teachers..

What is VIP? |

VIP is an affiliate of the Virginia Association of Science Teachers (VAST) dedicated to the development of Virginia's Physics and Physical Science teachers.

Mission

Our goal is to support the professional growth of Virginia physics teachers and to share the art/science of teaching physics with all teachers.

Description

"V-I-P" stands for the Virginia Instructors of Physics (and Physical Science). It is an organization for all levels of physics and physical science education in the state of Virginia. We connect high school physics and physical science teachers around the state with a network of colleagues, resources, and professional development opportunities. This is done through hosting of bi-annual meetings, one-day workshops, Facebook page (https://www.facebook.com/VAST.VIP), a yahoogroup listserv (http://groups.yahoo.com/group/va-inst-phys/), and a newsletter (http://vip.vast.org/NEWSLETT/2013spring/index.html). Membership is free to all educators teaching in the state of Virginia.

Join us at the VAST PDI

VIP will be offering a number of sessions at the VAST Professional Development Institute (PDI). This includes our General Share session, our Tabletop Lab session, and our Make & Take for elementary teachers.

Sign up for the PDI visit: http://www.vast.org/annual-pdi.html

First Lab Ideas |

-All contribute

You can turn the standard constant velocity car lab into a fun challenge. Have each group characterize their cars using measurements of distance and time, tables and graphs. In half of the cars take one battery out and replace it with a foil-covered dead battery. This will cause that car to go significantly slower. Then have them pair up with a group with a different speed car. Their challenge is to start each car heading toward each other with an initial separation of maybe 6-8 m and predict the place where they will meet. Bonus points for the closest groups. For those of you unfamiliar with "constant velocity cars", they are battery powered toy cars, trucks, etc that you can purchase at toy stores. Since it might be difficult to find a complete lab set in a store, it is better to search "constant velocity cars" and purchase online. We have the dune buggies from Arbor and are happy with them. They are $7 each if you buy 10 or more. http://www.arborsci.com/constant-velocity-car Wherever you decide to get them, always take them out and operate them for awhile to make sure they work. I can be hard to return defective items if you wait months to open them just before you need them. Dan Burns

Do measurement stations as a first lab. Put out whatever tools you have, balance scale, rules, graduated cylinders, etc, and several objects each to measure. Each member of a group measures each item. This allows the teacher to talk about how to get an accurate measurement, what is the precision and sig figs for measured and calculated values. Have the students average the values, write about why these values are usually better than a single measurement. Write about how each instrument works and is selected for the job. Have them create data and a graph by measuring values for increasing number of identical items, such a legos. This also gives you the opportunity to talk about properties that will affect the measurement, such as size, and those that won't such as color. The students can then create a best line fit and compare the value to others. -Ralph Cox

Flip a paper cup, place a ruler as a ramp from the cup to the desk, place a 1/2 cup (bisected on the z-axis) at the bottom of the ramp, roll 1-3 marbles simultaneously and see how far the 1/2 cup moves. The kids get about a half hour to "play", then they get the challenge: make the cup move x centimeters, where x is determined by random number generator. They only get one try. Then a new x is generated and they try again. The group that gets the least total variation from the target value wins.

The next day we repeat the experiment, but this time with data tables, graphing, error analysis, etc. in order to show the importance of using a systematic and analytic approach, controlling variables, to make predictions about the future.

We revisit the lab at the end of mechanics, where I have them use the same setup to determine the coefficient of friction of the sliding cup, which ties together work, energy, kinematics and momentum for a good summary of the first half of the course.

Equipment

A box of bouncy balls of varying bounciness, Masking Tape, Meter Sticks

Pre-Lab Discussion

Drop a ball from rest and from various heights in front of the class. Catch the ball at the peak of its bounce. While you are dropping the ball the students should be recording their observations in their lab book. Have the students share their observations with the class. Record the class's observations on the board.

Next repeat the demonstration with a ball of different bounciness. Ask the students to record the similarities and differences between the two demonstrations in their lab books. Have the students share the similarities/differences with the class. Record these on the board.

Guide the class to determine what can be measured about the observations made. Emphasize that students need to indicate what tool(s) they would use to make the measurements. This will helps the teacher should guide the class to the consensus that:

- Purpose – statement of the problem to be investigated, e.g. “to investigate how the bounce height of a ball depends on the drop height.”
- The independent variable for the lab is the drop height and that the dependent variable for the lab is the bounce height. Sometimes it is helpful for students to distinguish between the variables by stating the problem as: “How does the (DV) change if the (IV) is changed?” or “What is the dependence of the (DV) on the (IV)?” In the superball lab: “How does the bounce height depend on the drop height?”
- The constants for the lab are the ball used and the surface the ball bounces on.

Whiteboarding of Lab

Students should present their lab results on a whiteboard to the class. Some things you may want the students include on their whiteboards are:

Names, IV/DV, Constants, Ball Used, Where measurements were taken on the ball. (Top/Bottom), Graph of Results, Any Equations found, A few sentences discussing the results

The discussion can begin with the specifics of their results and progress to a generalization. It is important to help the students determine the general relationship between the variables tested and the physical meaning of any constants in their equation. Also, a discussion of error should be included.

Analysis of Data

In this experiment some students will make their measurements from the bottom of the ball and some will make them from the top of the ball. For this reason we will break of the analysis of data into two sections. The first section will be for those who measure from the bottom of the ball and the second section will be for those who measure from the bottom of the ball.

Measuring from the Bottom of the Ball

The graph/data table below is sample data for a ball dropped from various heights and measured from the bottom of the ball.

The equation for the above graph is

BH=(.5 cm/cm)(DH)+0 cm or BH=(.5)(DH)

BH=bounce height

DH=drop height

As can be seen in the above graph, the relationship between bounce height and drop height is linear. Or it can be said that the bounce height is proportional to the drop height. This linear relationship general holds up to a drop height of 3 meters.

The slope represents the amount of bounce height for every 1 cm of drop height. This represents the “bounciness” of the ball. The bouncier a ball the steeper the slope will be. Also the slope can be thought of as the percentage the bounce height is of the drop height. In this case the bounce height is 50% of the drop height.

The y-intercept for any group that measures from the bottom of the ball will be 0. When the ball is set on the floor the drop height and the bounce height will be 0.

Measuring from the Bottom of the Ball

The graph/data table below is sample data for a super ball dropped from various heights and measured from the top of the ball. The diameter of the ball is 10 cm.

When measuring from the top of the ball both the drop height and the bounce height will be increased by the ball's diameter. (When the ball is resting on the ground both the bounce height and the drop height would be the ball's diameter.) This results in the line on the graph being translated to the right and up which affects the y-intercept and makes the y-intercept positive. (See y-intercept explanation.)

The equation for the above graph is

BH=(.5 cm/cm)(DH)+5 cm or BH=(.5)(DH)+5 cm

BH=bounce height

DH=drop height

As can be seen in the above graph, the relationship between bounce height and drop height is still linear.

We can also see from the above graph that the slope is not affected by where you measured on the ball. The makes sense for two reasons.

First the slope represents the bounciness of the ball. Since the same ball is being used it has the same bounciness and therefore has the same slope.

Second, from a mathematical perspective by measuring from the top of the ball we simply translated the line to the right and up. Therefore the slope should not change.

The y-intercept for any group that measures from the top of the ball will NOT be 0. This will throw students for a loop. Students will initially want to make the y-intercept zero regardless of where they measure on the ball. Below is a mathematical explanation of why the y-intercept cannot be zero if you measure from the top of the ball. (m for any ball is always less than 1.)

If you measure from the bottom of the ball your equation will be:

BH=(m)(DH)+bbottom (bbottom=0)

Solving for bbottom we get

bbottom=BH-(m)(DH)=0

If you measure from the top of the ball all your DH and BH values have been increased by the diameter of the ball (d), so your equation will be:

(BH+d)=(m)(DH+d)+btop

Solving for btop we get

btop=(BH+d)-(m)(DH+d)

btop=BH-(m)(DH)+d-(m)(d)

btop=bbottom+d-(m)(d)

btop=d-(m)(d)

Joe Mahler

September Meeting |

Does the new AP Physics 1&2 curriculum have you worried?

Who is Welcome: Everyone is welcome to attended the meeting. Even if you are not a member of VIP.

Date: September 21, 2013

Time: 8:30 am – 3:00 pm

Place: JMU Physics/Chemistry Building

901 Carrier Drive

Harrisonburg, VA 22807

Professional Development: 6 Hours

Cost: There is no cost.

Description: The meeting will begin with demos that can be used to teach mechanics, followed by a short presentation/discussion about the new AP Physics 1&2 curriculum. During this time attendees will share what they know about the new curriculum and their concerns as they prepare for next year. For the remainder of the meeting we will begin developing a test bank of questions and inquiry labs that will be made available to all VIP members.. This will be an ongoing project that VIP hopes to complete by the end of the 2013-2014 school year. In order for this project to be successful we need your help! So come to the meeting and share your expertise and knowledge with your colleagues. Coffee and bagels will be provided in the morning as well as lunch.

Registration: Contact Joe Mahler, mahlerjm@jmu.edu, by email to register for the meeting.

October VIP Introduction to Modeling Training |

Modeling Activities To Teach Impulse and Momentum

Date: October 5, 2013

Time: 8:00 am – 3:30 pm

Place: St. Catherine’s School

6001 Grove Avenue

Richmond VA 23226

Professional Development: 8 Hours

Cost: There is no cost for the workshop.

Description: The participants will take on the role of high school physics students as the workshop instructors lead the participants through a series of modeling activities/labs that can be used to teach impulse and momentum (SOL PH.1-3 and PH.6). This will be a hands-on workshop and the participants will leave with activities/labs, student handouts, and instructional notes that they can immediately implement into their classrooms to enrich their curriculum. Coffee and bagels will be provided in the morning as well as lunch.

Registration: Contact Joe Mahler, mahlerjm@jmu.edu, by email to register. Registration will be first come first served and space is limited to 20 participants. We usually fill up early!

See you at the VAST PDI |

It is time to register for the VAST Professional Development Institute! (VAST PDI). The VAST PDI is the time and location of the VIP fall meeting and a place to grow in content knowledge, pedagogy, and network connections. There are approximately twenty physics concurrent session with three of them hosted by VIP. In addition to the physics sessions there are also several engineering and physics –integrated themed concurrent sessions. More to attend than you will be able to fit in your time there!

This year’s VAST PDI is November 14-16, 2013 at the Norfolk Waterside Marriott in Norfolk, Virginia. It should be a beautiful time of year to be at a beautiful location. Check it all out and register athttp://www.vast.org/annual-pdi.html

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