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What happens when you take some basic, introductory physics and apply them to cool things you see? Dot Physics happens. This blog looks at movies, experiments, demos and other topics typically aimed at the introductory physics level.
Rhett Allain is an Associate Professor of Physics at Southeastern Louisiana University. He
enjoys teaching and talking about physics. Sometimes he takes things apart and can't
put them back together.
October 29, 2008
Category: physics
I don't need to explain that I think the Mythbusters are awesome (do I?). I just finished watching their latest episode. In it, they tested the scene from Indiana Jones and the Last Crusade where Indy puts a flag pole in another motorcycle wheel. The result in the movie is that the motorcycle goes flipping in the air.
Posted by Rhett Allain at 10:46 PM • 2 Comments • 0 TrackBacks
October 28, 2008
Category: physics
Yes, I did some experiments with [Fantastic Contraption]
Posted by Rhett Allain at 9:46 AM • 0 Comments • 0 TrackBacks
Category: physics
In this post, I am going to explore the elastic nature of the "water-sticks". If you have played fantastic contraption, I am sure you noticed that the water-sticks are springy. How does these springy sticks work? Are they just like the springs we have in the real world? An excellent model for springs in the real world is Hooke's law. It says the force exerted by a spring is proportional to its stretch.
Posted by Rhett Allain at 9:04 AM • 5 Comments • 0 TrackBacks
October 26, 2008
Category: physics
In this setup, I have a "turning ball" with a wood stick attached to the side. I increased the length of the stick until the ball does not turn. At this point, the torque from the gravitational force on the stick is equal to the torque from the ball. I can use [Tracker Video Analysis](http://www.cabrillo.edu/~dbrown/tracker/) to find the lengths of the two wood sticks. The torque from each stick will be its gravitational weight times the perpendicular distance to the center of the turning ball.
Posted by Rhett Allain at 9:12 PM • 1 Comments • 1 TrackBacks
October 23, 2008
Category: physics
One of my students showed me this game, [Fantastic Contraption](http://fantasticcontraption.com/). The basic idea is to use a couple of different "machine" parts to build something that will move an object into a target area. Not a bad game. But what do I do when I look at a game?
Posted by Rhett Allain at 5:14 PM • 11 Comments • 3 TrackBacks
Category: science
I am sorry to point this out, but I can't help it. My kids watch this show "Fetch with Ruff Ruffman". It's mostly an ok kids show. However, there was a problem. In one episode, some kids were in the desert and measuring temperature with (they said it several times and it was even a quiz question at the end) - a LASER. Here is the device they used:
Posted by Rhett Allain at 8:44 AM • 0 Comments • 0 TrackBacks
October 21, 2008
Category: physics
[In a previous post, I talked about numerical calculations](http://blog.dotphys.net/2008/10/basics-numerical-calculations/). The basic idea is to use the momentum principle and the following "recipe":
Posted by Rhett Allain at 10:54 PM • 0 Comments • 0 TrackBacks
Category: physics
I know I should just let go, but this is what makes me, me. I understand that there are terms in physics (like for instance 'pressure') that are used in all sorts of ways in common language. The problem is when someone tries to explain something scientifically and misuses a word. Pressure means something. It is the average force per area due to collisions of a gas or liquid on a surface.
Posted by Rhett Allain at 8:57 AM • 2 Comments • 0 TrackBacks
October 20, 2008
Category: physics
[Previously, I talked about the momentum principle](http://blog.dotphys.net/2008/10/basics-forces-and-the-momentum-principle/). Very useful and very fundamental idea. The other big (and useful) idea in introductory physics is the work-energy theorem. Really, with work-energy and momentum principle, you will be like a Jedi with a lightsaber and The Force - extremely powerful.
Posted by Rhett Allain at 10:37 PM • 3 Comments • 0 TrackBacks
October 17, 2008
Category: random
This is not a "fix-it" blog. However, I think the Internet should be a useful friendly place. Think about the times you have had a problem. The Internet has been there for you - right? I remember not too long...
Posted by Rhett Allain at 9:09 AM • 1 Comments • 0 TrackBacks
denialism blog 02.14.2012
respectful insolence 02.14.2012
uncertain principles 02.13.2012
confessions of a science librarian 02.13.2012
starts with a bang! 02.13.2012
