1 day agoMember-onlyAll the Physics You Need for a Spy BalloonSometimes news items have some physics connections. That’s when you need someone to do some stuff. I’m that someone. In this case, it’s a large Chinese “spy” balloon floating over the USA. Chinese Spy Balloon or 'Civilian Device'? WASHINGTON - American military officials on Thursday said they had detected a "high-altitude surveillance balloon"…www.nytimes.com I’m not judging anyone. Maybe it’s a spy balloon or maybe it’s someone’s science fair project that got…Physics8 min readPhysics8 min read
5 days agoMember-onlyModeling a Bouncing Stick with PythonWhat happens when a stick falls and hits the ground? Really, this is only part of a bigger problem. I’m working on modeling this awesome Veritasium short showing two falling ladders. …Physics6 min readPhysics6 min read
Jan 27Member-onlyHow to Use Python as Your Physics CalculatorRemember when humans used to calculate all their stuff on paper? Or maybe they were super-tech savvy and instead used a SLIDE-RULE? OK, that was a little before my time. But then this new fancy thing came out. They called it an electronic calculator. Some people surely hated it, but…Physics9 min readPhysics9 min read
Jan 23Member-onlyForce of Constraint on a Disk Rolling Down an Incline Using Lagrange MultipliersHere’s a problem that might come up in many classical mechanics courses. It goes like this: A solid disk with mass m and radius R rolls down an incline. What is the force of constraint to make this roll? There is more than one way to answer this question —…Physics6 min readPhysics6 min read
Jan 21Member-onlyNewton’s Second Law in Spherical CoordinatesNewton’s Second Law gives a relationship between the total force an object and that object’s acceleration. I’m going to write this equation as I would in a classical mechanics course — I mean, let’s be real for second. If you are using spherical coordinates then you aren’t going to…Physics9 min readPhysics9 min read
Jan 16Member-onlyWhat Should You Use for a Gravity Demo?Let’s say I want to make a demonstration of the universal law of gravity. This law says that there is an attractive gravitational force between ANY two objects with mass. We can calculate the magnitude of this force as:Physics3 min readPhysics3 min read
Jan 11Member-onlyWould This Gravity Demo Actually Work?Yes, it’s a TikTok video — and obviously from some old science video source. But it looks cool. Here’s the basic idea for this physics demonstration. A small lead mass (they call it a pyramid) is suspended from a scale. It reads 152.166 grams. Next, a large lead sphere is…Physics5 min readPhysics5 min read
Jan 10Course Reflection: Classical MechanicsThe next semester starts soon — and I only have one course reflection from the fall semester. I better get on this quickly. This is the first semester of classical mechanics. What do we cover? Well, it depends. Normally, I start off trying to stick with the textbook (we use…Physics3 min readPhysics3 min read
Jan 9Member-onlyModeling 2D Motion in the xkcd What If-WorldThis is part 3 of my series on the xkcd What-If-World. Here’s part 1 an here’s part 2. Let me get you up to speed on this. Basically, the xkcd What If-World (that’s what I call it) is a web-based game that gives you a rocket that you can fly…Physics6 min readPhysics6 min read
Jan 4Modeling Rocket Thrust in the xkcd What If-WorldI’m still working on my PhD in xkcdology. That means that I play around with this What If? world and try to figure out how it works. Oh, you don’t know about this world? There’s really not much to know except that it’s a browser game that gives you a…Physics5 min readPhysics5 min read
