VicPhysics News: Term 2, No 3 2017
Dear ,
Table of Contents
1. A simple and quick Experiment on Coulomb’s Law
2. Forthcoming events for Students and the General Public
a) VCE Lectures for Students, Practical Investigation, 18th May, University of Melbourne
b) Small, Medium, Large: What Galaxy Sizes Reveal About Their Past, 6:30pm, Friday 12 May, Swinburne University
3. Forthcoming events for Teachers
a) ASELL Schools Workshops on Laboratory Learning, various dates and venues
b) Professional Learning Programs for STEM Teachers, full day, various dates from May to Dec, La Trobe University
c) The Sound of Science, 6pm, 14th June, Melbourne Recital Centre
d) ANSTO PD for teachers, Tuesday, 20th June, Australian Synchrotron
4. Physics News from the Web
a) How to weigh tiny objects using sound
b) The universe through a glass darkly
c) Snooker Physics
The next meeting of the Vicphysics Teachers' Network will be at 5pm on Thursday, 18th May at Melbourne Girls' College. All teachers are welcome to attend this or any other meeting. If you would like to attend, please contact Vicphysics at
Regards,
Frances Sidari (Pres), Jane Coyle (Vice Pres), Barbara McKinnon (Sec) and Dan O'Keeffe (Treas).
The executive of the VicPhysics atTeachers' Network
1. A simple and quick Experiment on Coulomb’s Law
If you bring a charged rod near the pan of a top loading balance, there is a measurable attractive force on the pan.
The Vicphysics Committee has used this phenomenon to develop an experiment on Coulomb’s Law. The experiment uses:
· a top loading balance,
· a charged rod and
· a laboratory jack
to measure the strength of the electrostatic force as the separation is varied.
The data can be analysed to determine:
· The value of the exponent for r in Coulomb’s law, and
· The quantity of charge on the rod, in Coulombs.
The experiment uses the equation for the attraction between a point charge and a conducting plane,
F = kQ2 / 4r2,
where Q is the charge on the rod and r is the separation.
The conducting plane is electrically equivalent to a plane mirror with an image charge of the opposite sign, but the same size equidistant behind the mirror, so the charge and its image are 2r apart, giving F = k x Q x Q/ (2r)2.
A sheet of metal is placed on the balance to provide a flat, large surface (15 x 15 cm should do). A charged rod will exert a measurable attractive force on the metal sheet from about 10 cm away, increasing as the rod is lowered to the plate.
Given the equipment needed, it may be best to do the experiment as a class experiment. A worksheet describing, the theory, equipment needed, method and hints is at http://www.vicphysics.org/fields.html#Electric.
Once the equipment is set up (before class) it takes only a few minutes to collect the data, with the rest of the time spent taking the students through the analysis. A curve fit of the data in Excel gives the value of the exponent. Results have been close to the expected value of 2 and when uncertainties are considered, the value of 2 is within the calculated range.
The equation of the trendline also gives the constant, which can be used to calculate the quantity of charge on the rod in Coulombs. This gives a physical meaning to the unit of a Coulomb and relates this to the physical effort in charging the rod.
Extension opportunities
· As a class experiment, the activity can be a useful opportunity to show students how to use Excel for recording and analysing data. It also effectively illustrates the value of a log-log graph.
· The charge of a charged rod, as measured by the balance reading, was shown to 'decay' with a half life of about 9 minutes. A more precise determination of the value of the exponent can be obtained by recording the time at which balance readings are made and calculating an adjusted reading on the assumption that the charge did not dissipate.
· The equipment setup also provides numerous possibilities for topics for the Practical Investigation. These are also listed in the worksheet.
· If an iron based metal sheet is used, then a comparison between the strength of electric and magnetic fields can be demonstrated.
Vicphysics would like to thank Camberwell Grammar School for the use of the labs and the advice of the Physics Department during the development of the activity .
2. Forthcoming events for Students and General Public
a) Physics Lectures for VCE Students: Practical Investigation, 6pm Thursday, 18th May, University of Melbourne
The upcoming lectures for the remainder of Semester 1 are:
May 18th The Practical Investigation with Dr. Syd Boydell
June 1st Electric Power with Assoc. Prof. Jeff McCallum
The lectures are held in the Laby Theatre in the Physics Dept at the university.
Youtube videos of the first two lectures on Motion, Thermodynamics and Relativity are available here. http://www.vicphysics.org/events-for-students.html
b) Small, Medium, Large: What Galaxy Sizes Reveal About Their Past, 6:30pm, Friday 12 May, Swinburne University
Please click on the link below to register:
https://docs.google.com/forms/d/e/1FAIpQLSdi9LwWv7EOfM-oNagQ9OAgE5W-dWU8ZFUoUuukVoN6_0ev0A/viewform
Presenter: Dr. Rebecca Allen, Centre for Astrophysics and Supercomputing
Abstract: Galaxies are the largest structures of matter in our Universe. Our own Milky Way has been studied in glorious detail. We know it has billions of stars, around most of which planets are likely to be found. There is a super massive black hole at its center where anything that gets too close will be consumed. There are intricate dust lanes that obscure the main disk of the galaxy. There is the life-force of stars, hydrogen gas. Finally, there is the mysterious dark matter that acts as a gravitational glue holding the ordinary matter together. But our galaxy is just one of many, and since their discovery, understanding how these complex objects form and evolve has been a focus of astronomers.
There are many pathways to reveal more about the nature and evolution of galaxies. In my talk, I will share how I use the sizes of galaxies to understand more about their growth.
Date: Friday, 12 May 2017
Time: 18:30 - 19:30
Venue: Swinburne University, Hawthorn Campus, ATC Building, ATC101 (enter from Burwood Road)
Map: https://www.google.com/url?q=http://www.swinburne.edu.au/media/swinburneeduau/about-swinburne/docs/pdfs/hawthorn-map.pdf&sa=D&ust=1493337997953000&usg=AFQjCNHD7M-D6MdeX3vxXPFnUWnBCIl1xg
3. Forthcoming events for Teachers
a) ASELL Schools Workshop on Laboratory Learning, various dates and venues
ASELL: Advancing Science and Engineering through Laboratory Learning
Workshops are FREE, however, participants are requested to commit to sharing their learning from the workshop with colleagues within their school.
The program includes hands-on sessions exploring exemplary practical activities targeted at the 7 – 10 science curriculum, as well as sessions investigating ideas for optimising science learning in the laboratory.
Morning tea and lunch provided together with comprehensive notes.
CRT funding support is available.
19 May 2017 Mary MacKillop College, Leongatha.
Online registration https://goo.gl/forms/zoSvn6ZQcR5AlvNW2
24 May 2017 Gippsland Grammar School, Sale
Online registration https://goo.gl/forms/S8UgZQ3QjIcJiXVJ2
1 June 2017 Oberon High School, Geelong
Online registration https://goo.gl/forms/x7esduIcINpMFRuv1
7 June 2017 Mercy College Camperdown
Online registration https://goo.gl/forms/SA9sOB2RAgXluPyg1
21 June 2017 Emmaus College, Vermont South
Online Registration https://goo.gl/forms/ADjfsr3EZ8eCgSuC2
The ASELL practical activities include integration of the Science Inquiry Skills, Science as a Human Endeavour and Science Understanding strands of the Australian Curriculum, and link to contemporary science.
For further information contact Ian Bentley
b) Professional Learning Programs for STEM Teachers, full day, various dates from May to Dec, La Trobe University
In 2017 La Trobe University is offering science teachers in Victorian high schools a suite of Professional Learning Programs (PLPs). The PLPs support and up-skill secondary teachers by reinforcing content knowledge and understanding of new technologies and teaching tools to build confidence in the delivery of Science, Technology, Engineering and Mathematics (STEM) education. The programs are designed to support teachers at all stages of their careers, from those just starting out to more experienced teachers. The emphasis is on Years 7 - 10.
Typically, the PLPs include an introductory lecture, practical workshops and opportunities for interaction with practising scientists and researchers. The presenters address current educational and industry context, new initiatives, and global trends, with a practical emphasis on classroom relevance. Teachers will return to their classrooms with fresh insights, renewed confidence, new ideas, and tools and techniques for communicating with their students.
Sessions run for a full day (9:00 to 3:30) and cost $250 per person. For more information on each program go to http://www.latrobe.edu.au/outreach/she-outreach/science or contact Madeline Toner, the Professional Learning Programs Coordinator on 9479 8922 or
Dates: Chemistry: 26th May, Physics: Friday, 16th June, Psychology: 21st July and 8th Dec (Bendigo), Engineering: 18th August, Maths: 24th November, Biology: 30th November
Venues: Melbourne campus at Bundoora, except for Psychology on 8th Dec in Bendigo.
c) The Sound of Science, 6pm, 14th June, Melbourne Recital Centre
In this exploration of sound and space, Cameron Hough, Senior Acoustic and Theatre Consultant with Arup, illustrates the science of sound. Find out how acoustic engineers design spaces for performing and listening to music, from the people who designed the Salon and Elisabeth Murdoch Hall at the MRC. Curt Thompson, Head of Strings at the University of Melbourne will supervise a string quartet to offer practical music and commentary during the session.
Cost $10.
To book http://www.melbournerecital.com.au/events/2017/musical-explorations-the-sound-of-science/
d) ANSTO PD for teachers, Tuesday, 20th June, Australian Synchrotron
Get some fresh ideas for teaching key areas of the Year 9 science curriculum and VCE Physics. Organised by the ANSTO Discovery Centre.
When: Tuesday June 20, 2017, 9am-3pm, Thursday November 16, 2017, 9am-3pm
Where: Australian Synchrotron, 800 Blackburn Rd, Clayton, Victoria
Cost: Free
Program: Coming soon http://www.ansto.gov.au/Resources/DiscoveryCentre/EducationResources/TeacherProfessionalDevelopment/Days/index.htm
Registrations: For June: https://forms-ext.ansto.gov.au/register/363 , For November: https://forms-ext.ansto.gov.au/register/364
4. Physics News from the Web
Items selected from the bulletins of the Institute of Physics (UK) and the American Institute of Physics.
Each item below includes the introductory paragraphs and a web link to the rest of the article.
a) How to weigh tiny objects using sound
b) The universe through a glass darkly
c) Snooker Physics
a) How to weigh tiny objects using sound
http://physicsworld.com/cws/article/news/2017/apr/11/how-to-weigh-tiny-objects-using-sound
A $12 device that can measure the mass of microgram-sized objects in fluid has been developed by researchers in the US. The sensor is driven by a piezoelectric speaker and measures the change in the resonant frequency of a glass tube as the object passes through it. The team used the device to measure mass changes in several biological samples and says that the sensor has applications in a wide range of fields, such as developmental biology, toxicology, materials science and plant science.
b) The universe through a glass darkly
http://physicsworld.com/cws/article/indepth/2017/apr/27/the-universe-through-a-glass-darkly
An extended review of 'The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars by Dava Sobel , 2017 Fourth Estate 336pp.
c) Snooker Physics
https://www.youtube.com/playlist?list=PLxZznBvU4YC_2tVnUkY4MD0D2dk_ECVKW
Five short Youtube videos on Snooker physics