Sequencing for Classical Mechanics

[CaptB]

Hello,

First time poster. I have taught High School Physics courses for 5 years now. I am interested in teaching it out of the typical order of Kinematics then Dynamics. This will be for next year if I go through with any changes.

I am interested teaching the beginning more like this:

Unit 1 -> Newton's 3rd Law - Forces, Systems, Vectors
Unit 2 -> Newton's 1st Law - Balanced forces and Inertial Motion
Unit 3 -> Newton's 1st Law - Unbalanced forces and Acceleration(Linear and Projectile)
Unit 4 -> Newton's 2nd Law - Dynamics
Unit 5 -> Work and Energy

I want the underlining theme to be Energy but not discuss in detail until work and energy unit.

Has anyone done this or have any references to research done on this sequencing?

 

[jedishrfu]

What is the goal of teaching like this?

Wouldn't it be better to follow some convention like say how Khan Academy approaches it? or your book?

I recall that when one of my HS teachers diverged from the book many students got lost when trying to study for a test, basically not knowing if some topic in the book was somehow missed in class and dilute their efforts by trying to study it.

 

[Dr.D]

I have never taught at the high school level, but my observation as a student myself, college professor, and engineering consultant is simply that for most typical dynamics problems, the most overlooked part is the kinematics. This is particularly true if there is anything more than rectilinear motion involved. For this reason, I would always begin with a careful study of kinematics.

 

[mpresic3]

How (do you forsee) your order will benefit your students. The order you suggest is very "force focused" for the first four units anyhow. Why not keep the conventional order. Students usually come with a better understanding of forces rather than energy. They experience force directly. Force on a book resting on a table; is mg. Energy of a book resting on a table, is mgh. Is h relative to the floor, the bottom of the Empire State Building, or the center of the Earth. Energy is tougher. It is better to address this students have some understanding of physics behind them. Your order does not place energy early anyway.

I have never taught HS, so I do not really want to present the counter argument above so strikingly, and I am interested in your motivation to change the order. I know in the student's chem class, (s)he has across Gibbs free energy, and Helmholtz free energy etc. I also know in most chemistry classes, the students learn how to calculate them, but they do not have the thermodynamic background to really understand them. I doubt you can build on the students understanding of Gibbs free energy or Helmholtz free energy in mechanics.

 

[Andy Resnick]

Hello,

First time poster. I have taught High School Physics courses for 5 years now. I am interested in teaching it out of the typical order of Kinematics then Dynamics. This will be for next year if I go through with any changes.

I am interested teaching the beginning more like this:

Unit 1 -> Newton's 3rd Law - Forces, Systems, Vectors
Unit 2 -> Newton's 1st Law - Balanced forces and Inertial Motion
Unit 3 -> Newton's 1st Law - Unbalanced forces and Acceleration(Linear and Projectile)
Unit 4 -> Newton's 2nd Law - Dynamics
Unit 5 -> Work and Energy

I want the underlining theme to be Energy but not discuss in detail until work and energy unit.

Has anyone done this or have any references to research done on this sequencing?

I haven't taught the material in that order, but don't see anything inherently problematic. The progression of units 2-4 can work: begin with dp/dt=0 and end with dp/dt = F. Since I don't know anything about your students and their preparation/motivation, it's hard to comment further on the pedagogical choice.

However, there are a few other points you may need to consider. First, are there any applicable content requirements in your school district (or state guidelines)? Second, your Unit 1 begins with 'Force', but that isn't defined until your Unit 4- how exactly will you talk about 'force'? Last, it's hard for me to understand what you mean by 'underlying theme to be energy' when units 1-4 are not concerned with energy.

I'm always in favor of trying new things- go for it!