Author Archives: Andy Rundquist

About Andy Rundquist

Professor of physics at Hamline University in St. Paul, MN

AppSheet ideas

Posted on April 14, 2024 by Andy Rundquist

AppSheet is a google product that enables you to use Google Sheets as a backend database for a mobile app that works in both the Android and Apple ecosystems. I encourage you to check it out, as it’s become a … Continue reading →

Posted in community, programming, technology | 3 Comments

Constraint forces for path in 3D

Posted on March 3, 2023 by Andy Rundquist

This is a post mostly for my future self. What got me thinking about it was this comment about my planetary tunnels post: which is actually referring to a really old post of mine about how to dig a well. … Continue reading →

Posted in math, mathematica | 1 Comment

Does the hoop hop?

Posted on February 28, 2023 by Andy Rundquist

I greatly enjoyed this recent video from StandUpMaths: The set up is a hoop with a mass attached at one point. It’s rough so it rolls without slipping. It’s released with some angular momentum with the extra mass starting at … Continue reading →

Posted in general physics, math, mathematica, physics | 1 Comment

Planetary tunnel oscillators

Posted on February 26, 2023 by Andy Rundquist

Pick a point on the earth and start digging. It doesn’t have to be straight down. Keep it straight (careful! it’s harder than you might think) and keep going until you come back to the surface. Ok, now drop a … Continue reading →

Posted in general physics, mathematica, physics, teaching | 2 Comments

Dropping ladders

Posted on February 25, 2023 by Andy Rundquist

My friend Rhett Allain has really got me interested in this ladder drop posted by Veritasium: Here’s Rhett’s awesome explanation: Of course I wanted to see if I could model it with Mathematica, and, after finding I could run Mathematica … Continue reading →

Posted in general physics, mathematica, physics, teaching | 2 Comments

Mathematica for free

Posted on February 23, 2023 by Andy Rundquist

In this post I’m going to try to capture the steps I took today to get a Jupyter Notebook to run Mathematica commands. I did it on a Windows laptop so if you’re on a Mac of Linux you’ll have … Continue reading →

Posted in computational data science, mathematica, programming, teaching | 12 Comments

Computational Data Science capstone class

Posted on January 15, 2023 by Andy Rundquist

In just over a week the CDS capstone class starts and I’m not nearly ready. It’s been a while since I taught a class (Spring 2021 in the pandemic) and I’m a little rusty. But I remembered how useful it … Continue reading →

Posted in computational data science, sbar, sbg, syllabus creation, teaching | 2 Comments

Rolling without slipping on curved surfaces

Posted on December 31, 2022 by Andy Rundquist

I’ve been trying to see if I can model balls rolling on curved surfaces and I think I’ve cracked it. Here’s a teaser to get you interested: What you see is a sphere rolling on a curved surface. The blue … Continue reading →

Posted in fun, general physics, mathematica, physics | Leave a comment

Situations that share equations of motion

Posted on December 9, 2022 by Andy Rundquist

Recently my friend Rhett Allain has been making some awesome videos showing how to solve complex problems with a Lagrangian approach. I love it when he posts a new video because it usually motivates me to try to model something … Continue reading →

Posted in mathematica, physics | 3 Comments

Rigid bodies, formulation and examples

Posted on November 25, 2022 by Andy Rundquist

My friend Rhett Allain gave me a good challenge recently with this tweet: I had been working on a problem that he posted about regarding a bead sliding freely on a hoop that is spinning about an axis in its … Continue reading →

Posted in mathematica, physics, syllabus creation, teaching, twitter | 1 Comment