# Category Archives: general physics

## Does the hoop hop?

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

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

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

## Rolling without slipping on curved surfaces

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

## Shooting circuits

I’ve posted before about how I struggle teaching complex circuits (really just circuits that contain batteries and resistors in ways that can’t be analyzed with parallel and series tricks). There you’ll read about how I find that if I just … Continue reading

Posted in general physics, physics | 8 Comments

## Doppler Drum Corps

One of my favorite oral exam questions to give students in introductory physics classes is to ask them whether marching bands should worry about tuning because of the Doppler Effect (lots of details below but the short version: if there’s … Continue reading

Posted in fun, general physics, mathematica, parenting, physics | 6 Comments

## Mass changing orbits

A few weeks ago my good friend John Burk posted some intriguing questions about what happens to planetary orbits as the sun loses mass (all that heat has to come from somewhere!). I’ve been thinking about it ever since and … Continue reading

Posted in general physics, mathematica, physics | 2 Comments