Dot Physics

Archives for February, 2010

I ride my bike and mostly the wind makes me unhappy. On a very few days the wind is with me on the way to work and then changes so that it is with me again. But most days the wind is fairly constant. So, if the wind is constant then shouldn’t everything even out?…

Another Take on Homework

I thought this was an interesting idea. One of my colleagues does not collect homework. Instead, the students turn in a sheet that lists which homework problems they worked on and how much time they spent on homework. By doing this, the students get a small homework grade – independent of how much time they…

Faster than terminal velocity

I had so much fun creating graphs for the Red Bull Stratos Space Jump calculation, that I figured I should make some more. Can you fall faster than terminal velocity? That is the question. Air Resistance Air resistance is a force exerted on an object as it moves through some stuff – air in this…

Ski jump landing and acceleration

My last Olympics post may have been a little complicated. I am going to try to make this one a little easier. In this post, I want to look at the landing portion of a ski jump. This could apply to THE ski jump, but there are some things in that even that make it…

Bloggingheads Diavlog

The kind folks over at BloggingHeads TV were nice enough to offer me an opportunity to discuss some science stuff with Ed Grabianowski from io9.com. Here it is: In this discussion, we talk about: Learning physics and physics education research The value of science educators Good and not so good science on TV Journalism and…

Stratos Space Jump

Red Bull is sponsoring this sky dive from really really really high up – Stratos: Mission to the Edge of Space. Seems dangerous. The basic idea is that Felix Baumgartner will take a balloon ride up to 120,000 feet and jump out. Here are some questions: Will he reach supersonic speeds? The Red Bull site…

Apolo Ohno Physics

It is winter Olympics time and time for physics. The event that I always gets me thinking about physics is short track speed skating. It is quite interesting to see these skaters turn and lean at such high angles. All it needs is a little sprinkling of physics for flavor. Check out this image of…

Mardi Gras Physics

Do you need some physics to go with your beads? Well, here it is. Actually, I will let you do the physics (for now – meaning if you don’t analyze these, I will). Here are some pictures of a broken strand of beads. I hung them on my fence – you know, for display. Click…

Simple Experiments with Friction

Now I get to do something with that force scale I built. I had a request some time ago to talk about friction. Friction is surprisingly complicated. When two surfaces rub against each other, why is there a friction force? The basic answer is that the stuff the two surfaces are made of (atoms) are…

DIY Force probe

I was thinking about some experiments that deal with friction and I wanted to show something with a force probe. The problem is that most people don’t have one of these. So, I decided to try and make one out of simple things. In this case, I am using some straws, a rubber band and…