accelerometer
rallain | May 20, 2010And there's parliament. Ok - sorry, I had to make a "Tom (Swans on Tea)" title for this one. Tom, forgive me.
Here are two great circular motion videos. First, this one is from Dale Basler. He made himself a fine little floater-type accelerometer. Better than just make it, he made a video of the accelerometer in his car going around a round about. Check it out.
Bobber Meets Roundabout from Dale Basler on Vimeo.
So, if he is driving at a constant 10 mph, how big is the round about (traffic circle)?
Next video - more silly kids
First, I saw this one on ZapperZ's Physics and Physicists who…
rallain | April 28, 2010You see in my experimental determination of the location of the accelerometer in an iPod, I used two different iPhone apps. Let me briefly mention some of the free iPhone apps that give you acceleration data.
AccelGraph: This is one of the apps I actually used. What do I like about it? Well, it can record x, y, and z acceleration data and then you can email it to yourself. What could make it better? How about a timed start to record (like start recording in t seconds) and a preset record time. This would allow you to set up your experiment and get your iPod set up before you start. As…
rallain | April 27, 2010There are several free iPhone-iPod Touch apps that let you look at the acceleration of the device using the built in accelerometer. I was planning on reviewing some of these free apps, but I didn't. When I started playing around with them, it was clear that I needed some way to make a constant acceleration. There are two simple ways to do this - drop it, or spin it in a circle. I decided to go with the circular motion option because I like my iPod and because Steve Jobs told me to.
While playing with this, I realized that the acceleration depends on the distance of the sensor from the…
rallain | July 21, 2009So, I built a new accelerometer. Why? The jelly-jar one was just not doing it for me. Plus, the cork was starting to make the water all yellowy. It was a good start, but I can do better. What was wrong with the jelly-jar one? First, it didn't let the cork move very far before hitting the wall. Second, it was kind of hard to see exactly where the cork was. Lastly, there was no way to get a reading of the acceleration from the jelly-jar. Now, I am going to fix that.
My new design uses a sphericalish glass flask. The floating bob is anchored in (near) the center of this sphere. Here…
rallain | July 14, 2009This has been on my list for quite some time. Really, it must be since i posted about measuring acceleration in free fall with an iphone. So, this post will be all about accelerometers.
How does an accelerometer work? Really, an accelerometer measures force some way on a known mass. Let me show an extremely simple accelerometer - a mass on a spring.
(image from Science Buddies where they have instructions on building such a device)
Suppose I put this accelerometer in a stationary and non-accelerating elevator. Let me draw a free body diagram for the mass on the end.
No magic here,…