On the Surface

Interactions between two surfaces, or coefficients of friction, has been a difficult topic for some of my physics students.  Thanks to online resources from The Physics Aviary,  Vernier Scientific, and The Physics Classroom, I found a sequence of activities that really made this concept crystal clear to my students and that included a very timely real-world application.

We usually start with a lab to determine the coefficient of static and kinetic friction between two surfaces by using a block of wood and spring scale.  This year, I used the Physics Aviary’s Friction Lab simulation that “uses” a Vernier Dual Range Force Sensor and a Labquest 2.   Students “pull” a block (with the force probe) across a surface.  As the tension increases, the block begins to move.  The block then moves at a constant speed.  A graph of tension vs time is produced.  Using this data and the normal force of the pulled block, students can determine the coefficients of static and kinetic friction.  Students can also change the size of the block, mass of the block, and the types of surfaces in contact with each other with this simulation. 

After students understand how to determine coefficients of friction, we do a “Mu of Your Shoe Lab” using the same type of equipment from the simulation.  Students determine the coefficient of friction for various types of shoes.  The Physicsclassroom.com has a nice version of this lab.  Vernier Scientific does a helpful video about this lab.  The video is designed for the middle school version of this lab, but there are some great tips for this lab.  When my students did the “Mu of Your Shoe Lab” after the simulation, there was less confusion about the procedure and the lab produced better results.

I added a final component to the lesson this year.  Any discussion of coefficients of friction always include those of various types of road surfaces. We had an early snow this winter and a record-breaking amount of rain this year, so talking about different driving conditions was very relevant!  The Physics Aviary has a simulation that brings the stopping distance for a skidding car together with the mass and initial speeds of the car, and different types of road surfaces.  Students study how each of these variables affect the stopping distance of a skidding car.  A link to the Hyper Physics Friction and Automobile article was added to prompt student reflections about the lesson sequence.

January 2: World Introvert Day and Engaging Introverts

Today is another holiday, but it does not require the planning needed as for the holidays.  It is World Introvert Day and the joke is that everyone celebrates this all by themselves.  Ha, ha.

I love this day of reflection and focus on introverts.  I am an introvert and I work in an environment that favors extroverts.  No problem on most days.  There are times, however, when my extroverted colleagues do not understand how mentally draining constant, engaging interaction can be to us introverts.  We make up 25-50% of the US population according to Psychology Today.  As an adult, I have learned to cope with overwhelming interactions, but our students may not understand how to do so. 

Last March, Edutopia posted an informative article about how to help our introverted students in a world of collaborative education.  Introvert-Friendly Cooperative Learning has some great strategies to consider.  It reminds me to be cognizant of students who hesitate to work with a new lab group or who shy away from group quizzes.  As my classroom is set up in tables that face each other, I demand that students work in groups.  Today as World Introvert Day is a good reminder for me to consider how I would like to be a student in my own classroom. 

A final thought:  the Ted Talk on “The Power of Introverts” is also helpful for teachers when considering our “quieter” students.

Happy World Introvert Day!

Welcome to 2019: Day 1!

Brave teachers who share their ideas on social media have inspired me countless times.  Now, prompted by Neil deGrasse Tyson’s tweet about the Roman coin with the head of Janus – I am looking forward and backwards.  I am encouraged to reflect on what I have done and will do:  hence, my first blog post about teaching.

I thought by the time that I reached thirty years of teaching that I would have more answers than questions.  Not true.  I am constantly baffled by my subject matter, students, fellow teachers, parents, and administrators.  My colleagues can be helpful.  If you are fortunate enough to teach the same subject as other teachers in your school – you share ideas and solutions.  In a former life, I taught chemistry with amazing, creative, and giving teachers.  Now, I teach physics and it can be a lonely existence.

Enter the Internet.  Twitter.  #modphys and #iteachphysics are just a few of the lifesavers that I have found.  Blogging.  There are generous teachers who share their ideas.  I have been inspired and used their work with my students.  It is time that I shared my story and perhaps another teacher may benefit.  Who knows.

What I do know is that what we do in the classroom matters.  Sometimes it may seem like academics is not a priority – but it is.  Maybe you are the only physics teacher in your school, or the only teacher who seems to demand academic rigor, or the only teacher who is grading math or English homework during your lunch period – do not feel alone.  We are all in this together as we do this for our students!   As 2019 begins, let’s keep the magic happening in our classroom.  Do it anyway because It really does matter!