Tch Fzx - Forces First

I grew up in NY and took state-wide Regents exams in High School for all my major subjects.  That meant three Math, one Literature, one Social Studies, one Spanish, and four Science exams.  They were all end-of-year cumulative finals and the teachers had to get us ready.  I thought I was quite well prepared academically for my university experience compared to my PA classmates at Grove City College.

I used to credit that preparation to my New York State of Mind Regents education.  Looking back from farther in the future I now understand that the Corning-Painted Post School District, home of Corning Inc. and Ingersoll Rand, provided a high quality education for those students who were willing to work.

I found myself surrounded by supportive parents, good teachers, and like-minded students who all believed strongly in the importance of education.  We supplemented our textbook with paperbacks like these - published specifically for New York.

I still use those books periodically.  They follow what now seems the standard curriculum order for mechanics - no real physics until chapter 3 in October.

No Fzx til chapter 3

It's a struggle doing it this way.  Math tends to turn off the average student and it doesn't excite the better ones.  Strict definitions do the same and the first two or three chapters of most modern texts are all about definitions and equations and math.  We set up our students to believe that physics is all about writing like a lawyer and computing like a mathematician.

It's wrong.

Fortunately for Physics, I am unfettered by any encumbrance such as a standardized test or a scripted curriculum.  I can freely experiment with style and content along with curriculum scope and sequence.  I am an angel (or an obtuse angle) floating above the fray; observing and experimenting just like any experimental FZXst should.

I already dropped any requirement for constant or equation memorization since it's on their phones anyway.  I use an expanded version of the Regents Reference Tables in class.  It's on to Forces First

SOME HISTORY
I started my career with a book that did static and dynamic equilibrium and Newton's Laws first.  We adopted new books a couple years later and couldn't find a similar text.  We moved on to the modern standard curriculum.

No Fzx til chapter 4

I made another foray into "Forces First" a decade later but it didn't go so well.  YouTube didn't exist, a few people had videodisc players, DVDs were a new item, and we had just recently received school email addresses.  It was conceptually better and had more continuity but it didn't work for lack of supporting materials.

I GAVE UP AGAIN and went back to the textbook since my students need independent support materials.

It's now my 23rd year of teaching physics.  Now I have three YouTube channels, a Twitter feed, this blog, and BlackBoard.  We're moving to Google Classroom and iTunes U is always an option.  Everyone gets an iPad next year.  Now there's no shortage of access to supporting materials for whatever I want to do.

So I TRIED IT AGAIN last year cuz I can't past the frustration that kinematics and free fall and projectile motion prior Newton's Laws of Motion are just stupid math and vocab.  WE SHOULD BE TEACHING PHYSICS FROM DAY ONE.

• First a relationship between weight and mass by weighing and massing stuff since since that's actually useful.  W=mg.
• Static EQ - simple one-object and two-object FBDs - 1D zero net force
• Static EQ - tension and 2D FBDs
• Static EQ - inclined planes
• Static EQ - torque, CG, and beams - extended object FBDs and structures
• Simple Machines - two weeks of my favorite subject
• Dynamic Equilibrium - all the above at constant velocity - this is short and mainly a review of Static EQ and FBDs

I must mention that I didn't specifically define mass or weight or force or net force or Newton's First Law or the first and second conditions for equilibrium until I got to torque.  And then I only named the first and second conditions for equilibrium since we were doing it.  It was all doing and thinking with little defining and and as many math tricks as possible.  Even with the trig I just taught them a procedure that works and mostly ignored the "proper" math.  It worked well.

• We then did navigation and vector play.  Boats and planes.
• 2nd Law - net forces and acceleration with all the above minus rotation - you could do angular acceleration here too but it's a bit complicated with moment of inertia.
• 3rd Law - specifically defined and dealt with using two object systems - two blocks, string connecting two blocks and one falls.  Two blocks connected by a string on two separate inclines.  FBDs everywhere.

Now that they understand forces and why things move we can do a quick and dirty kinematics section where we focus on the vector nature of velocity and acceleration and constantly remind ourselves of the reason for motion and non-motion. 

• velocity vs acceleration vs displacement.  Using Vernier equipment and the iPad and the graphs generated we can go straight from the graphs to an understanding of the vocabulary and the equations.  It seems backwards but it's far better than "definitions first."
• some problems with equations but not a lot.  More focus on graphs and graph interpretation and doing labs of various types to prep for free fall and projectiles later.

We can go through this quickly and continually remind them that these are applications of Newton's Laws with acceleration.  About now it's time for a bit of rotational motion as another application of Newton's Laws.

• Centripetal force conceptual and FBD intro with lab on centripetal force.
• Problems and applications - FBDs every day
• Gravity and satellites with FBDs, Kepler's Laws with FBDs, and Newton's Law of Gravity with FBDs.

It is there that we differentiate between tangential and centripetal velocity and acceleration.  It's important for real elliptical orbits  and projectiles.  FBDs forever.  Then we do local gravity:

• Free fall with lots of play and graphs and problems
• projectiles with video and graphs and practical solutions

Then we get to the conservation laws.  Momentum first since it's all vectors.

• We basically skip impulse-momentum since it's just another 2nd Law statement.  We go over that idea, apply it to classic vs. modern auto safety features and use it to develop the 
• Law of Conservation of Momentum - with pictures - minimal algebra - 1D and 2D
• Here is a story on the method
• The emphasis on vectors and FBDs continues.

Energy is not a vector

• We start with work and power using vectors and FBDs
• Introduce net work = change in KE    (it's NOT work = KE!)
• Conservation of energy problems and ideas.

Through it all was forces and net force and free body diagrams.  And NET force and NET impulse and NET work.  That's some physics most textbook writers get wrong.  It was applications of Newton's Laws of Motion.  It was all connected.  Continuous.  It followed a single physics theme.

I FELL IN LOVE WITH forces first AND WILL DO IT THAT WAY UNTIL THE DAY I DIE.  Or retire.  Or get tired of innovating.

I did minimal work on rotational motion this year - I'd like more.  Then we did electricity and stuff.  Then I dislocated my shoulder twice and had surgery.  22 days absent with almost all in the second semester.

And all that happened only because I am not beholden to a state test.  I love the Regents system.  I got a great high school education but it tends to force conformity and suppress innovation.

FREEDOM!