Conceptual Understanding in Introductory Physics XXXIV: Parallel and Perpendicular Components of Force

Draw an arrow representing an arbitrary force vector and another arrow representing an arbitrary momentum arrow. Label both arrows. Ask the student to perform the following task: Decompose the force vector into a component parallel to the momentum vector and a component perpendicular to the force vector. Tell whether or not the given force will […]

Conceptual Understanding in Introductory Physics XXVI: System Schemas

This question might serve as a final exam for an introductory physics course. It could serve that purpose for my own courses, but it may not be appropriate for your courses so don’t worry if that’s the case. If you do not include system schemas in your course then this question won’t make any sense […]

Conceptual Understanding in Introductory Physics XXII: Energy in Multiparticle Systems

This question was prompted by the treatment of energy concepts in traditional introductory textbooks. Most such treatments tend to share an error in reasoning when it comes to applying energy principles to systems consisting of more than one particle. I may need to come back and edit the question so that it more accurately articulates […]

Conceptual Understanding in Introductory Physics XXI: Deriving Expressions for Kinetic Energy

Okay this may not be the most interesting thing to think about, but it’s a question I’ve been asked on several occasions. For that reason alone, I started thinking about it. I also think it’s another situation where coordinate-free vector manipulation can simplify otherwise messy questions and problems. So, here’s the question. Give three different […]

Conceptual Understanding in Introductory Physics XX: The Laplace-Runge-Lenz Vector

This post is inspired by the October 2015 AstroNotes in The Physics Teacher. I have sometimes introduced vectors into my introductory astronomy course and students were able to do most of the things described below. We never discussed angular momentum or the Laplace-Runge-Lenz vector, but the other quantities were familiar. I was not permitted in […]

Conceptual Understanding in Introductory Physics XV: Symmetry Arguments

Symmetry is part of the foundation of contemporary physics, but it is seldom emphasized in introductory physics in proportion to its significance. There may be some value in discussing how symmetry applies to otherwise traditional introductory problems rather than just replicating numerical examples from a textbook (even a good textbook). These questions illustrate symmetry in electromagnetic […]

Conceptual Understanding in Introductory Physics XIII: Differential Equations

This question may very well be beyond the scope of a traditional introductory calculus-based physics course, but given the recent trend in early introduction to computational physics with curricula like Matter & Interactions it may be within the scope of a reformed course. In classical physics, finding a particle’s trajectory under the influence of a […]

Conceptual Understanding in Introductory Physics X: Resolving a Vector

For this post, I decided to ask what I think is a very simple question. It is simple at first, but it also gets to the heart of the meaning of vector quantities, at least as they are typically presented in introductory physics. It also emphasizes the fact that vector quantities have an existence all their own, […]

Conceptual Understanding in Introductory Physics III: Interpreting Physical Quantities

This series continues with a question which, I hope, causes readers and students to reflect on something that is frequently omitted from traditional introductory physics courses. I contend that words are all we have to convey conceptual understanding in physics or any other topic. Yet, in science courses, and especially in physics courses, we tend […]