analysis

This idea comes from my friend Thomas. His son is like mine in that they both think LEGO are awesome, and they are correct. For some reason, Thomas decided to calculate the price per piece of LEGO in each set. To promote repeatability, I decided to do this also. Looking at the catalog at LEGO.com, I can get both the price of each set and how many pieces it has. Just a note, I looked at almost all of the Star Wars LEGO series and some other select themes. I didn't include any sets that had been marked down in price. I will put the first plot on down below, maybe this would be a good…
A couple hours ago I posted a quick poll, in what might be construed as an unbiased fashion. I simply asked respondents for their sexual orientation, offering a wide array of choices ranging from "straight" to "mostly gay" to "gay" to "other." In fact, my poll was biased -- not because the question itself was slanted, but because of the way respondents were recruited: I titled the post "Are you homosexual?" Potential respondents who are homosexual or who don't have traditional sexual preferences are more likely to be interested in the question, and therefore more likely to respond. How do I…
I enjoyed the super bowl commercials for the most part. You have to be careful not to have too high of expectations, or you will set yourself up for a big letdown. Here is a quick analysis of one of the commercials. This is a Bud Light commercial where at the end they throw a guy out of an office window because he suggests they save money by not buying beer. Are there any actual office meetings that serve beer? (Sorry if I spoiled the ending for you) I am going to analyze the motion of the guy going out the window. Just because. At some point in the future, I am going to make a short…
I said I would come back to this, and I am. I am a man of my word. Yesterday, I posted a link to a video of this really cool water rocket thingy. How does this work? What is the physics going on here? I think this can be best explained with the momentum principle. Let me start by pretending like I have some object that shoots out a piece of water (or really it could be anything). Also, let me pretend like this is in space ore something where there are no external forces. Above is a before and after picture. Initially, there is something (the box) with water inside. Through some process…
We have all seen the Kobe Bryant video of him jumping over an Aston Martin - this keeps coming up on the Internet. There has been vast discussions of whether this is real or fake. I will do my best to examine the evidence. In short (in case you don't want to read the whole thing) Kobe can most likely really jump that high, it is possible that there was some perspective trickery involved. Here is the video in case you are brand new to the WWW: Oh - don't forget I already analyzed Kobe Bryant jumping over a pool of snakes. I voted that was real. First, let me give a personal note to Kobe and…
When you pour a beer, there is this foamy top called the head. The size of the head decreases over time. What is this process dependent on? Clearly, little bubbles of beer are popping. Does each bubble have an equal probability of popping? Do only the bubbles on the top (or bottom) pop? I became aware of this idea from a colleague. Maybe he was going to do an analysis, but I haven't seen it yet. If you do (Gerard), I am sorry for doing this before you. This may have been investigated before, but in the spirit of re-doing everything I have not searched for previous beer head studies.…
I just can't pass this up. One of the chemistry majors had a complaint with the power company. After an unusually high previous power bill, they checked the electric meter half way through the month. The meter said they had used 90,000 kilowatt-hrs of electricity. That is a lot of energy. It is also a lot of money. If I estimate 10 cents per kilowatt hour (the prices varies in space and time), this would be a $9,000 bill. So, what is the deal? Is it a broken electric meter? Could be. If it is not, maybe it is a short. Shorts usually blow a fuse, but if it were an older house, could…
So, here is a video (from break.com - so you know it is likely fake). null - Watch more free videos If for some reason, you can not view this video, here is the plot. Guy wears parachute and brings a portable thing like a see-saw. Guy approaches large crane dropping a large mass repeatedly (I assume to flatten a dirt road) Guy sneaks up an puts the see-saw under the area that the mass drops on and then stands on the other end of the see-saw. Mass drops, guy shoots up and parachutes down. So, why is it fake? I think the best thing is to give an analysis of the see-saw. To start this analysis…
I saw this video posted on Physics and Physicists: It reminded me that I had at one point tried to analyze this. I had actually posted something about this on the first generation of my blog (which no longer exists). I have found the analysis, and here it is from the archives. Thanks ZZ for reminding me. Could this be true, or is it fake? I started to do an analysis of the trajectory, but I found the following frames: Look at the guy's back. His back starts moving before the water bottle rockets. It must be some type of cable pulling him. If the rockets were propelling him, the rockets…
I finally saw the movie Iron Man. It was good. I feel that I am qualified to evaluate the movie. When I was in high school, I was totally into comic books. Mostly Spider-man, but I still have a significant collection of Iron Man comics. Ok, now you know I am not an Iron Man attacker. I will now attack the movie. Sorry, it's what I do (remember, I already said I liked it). There are several things I could comment on, in fact I recall some other blog talking about the physics of Iron Man. My attack will center on the scene where Tony Stark (Iron Man) escapes from captivity with his home…
College football season is coming to an end (I guess technically, the season is over - it is bowl season). Anyway, this is something I wanted to do a long time ago, but I kept getting side tracked. If I don't do it now, I will never do it. Most people know that a ball without air resistance (traditional projectile motion) goes the farthest if you throw it at a 45 degree angle. What if there is air resistance? Why is 45 the best angle without air resistance? What other questions are there? I posted about projectile motion before - so you might want to start there. When people say "…
Clearly, I am not a professional blogger. I am an amateur. This is because I was under the impression that only amateur bloggers could compete in the blogging olympics. When did they change these rules? Anyway, Adam Weiner did a physics-based analysis of the latest Star Trek movie trailer. Here is the trailer: In the trailer (oh, spoiler alert) a young Kirk jumps out of a car before it goes over a cliff. It does look odd, and that is why I had intended to analyze it. In Adam's analysis, at PopSci.com the basic approach was: Take the initial velocity of the car (from the clip) Assume the…
This is an old video, but still interesting. In this video clip, Kobe Bryant jumps over a pool of snakes. You are probably thinking what I thought when I see that - this doesn't look real. Really, it must be fake. Why would Kobe jump over a pool of snakes? Isn't that dangerous (even if there were no snakes in there he could hurt himself). Video analysis is needed. Is this fake or is it real? Start with my favorite video analysis tool (tracker). Use this to get position time data. Step 1: Get the movie. I used Mpeg Streamclip to get the movie in quicktime format from the flash video…
Here is a video of a guy jumping 35 feet into a pool of water only 1 foot deep. UPDATE: Apparently, that video went away. Here is another version. How does this work? I don't think I even need to do a video analysis of this motion, all the important info is given. I will assume that air resistance did not play a signficant role (and that is a good assumption - or good enough - see this for example: motion of a falling tennis ball). So, here is the situation. Part 1: guy falls 35 feet 5 inches (10.8 meters). ![Screenshot 16sd](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/11/…
On MythBusters this week, Adam and Jamie tested the bullet-proofness of various objects. The one that sticks in my mind is the ipod. The said there was a report of a solider being shot by an AK-47, but he was saved because the bullet hit his ipod. To test this, Adam shot an AK-47 at an ipod and it went through. Their conclusion was that he was also wearing body armor. I am not sure I like that conclusion. Why would someone report that the ipod saved him if he was also wearing body armor? Maybe they would, but not sure. I was thinking, maybe the bullet went through the ipod because they…
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. I have no problems with their test - it seems like they did a decent job. However, in the end, Adam says something to the effect: *"Look how high that bike went. It took a lot of energy. There is no way that energy could come from this stick I shove into the wheel."* I am…
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? I think - hey! I wonder what kind of physics this "world" uses. This is very similar to [my analysis of the game Line Rider](http://scienceblogs.com/dotphysics/2008/09/the-physics-of-linerider/) except completely different. Fantastic Contraption gives the unique opportunity to build whatever you want. This…
Which wastes more fuel? (and thus produces more carbon dioxide). This is a difficult to question to answer for a variety of reasons. The main reason is that a speed change from 71 mph to 70 mph is different than a reduction from 56 to 55 mph. First, let me be clear that the question of how much fuel is wasted using daytime running lights (or DRL as they are called) has already been addressed. The first source I found was howstuffworks.com **Assumptions** The daytime running lights on a car run at about 100 watts (for the pair) The energy density of gasoline is 1.21 x 108 Joules/gallon. A car…
Can you believe it? Have you seen this video? Are you thinking what I am thinking? WOW. How could these people not follow my rules for cool internet video. Once again, here they are: 1Keep the camera stationary. This way I don't have to keep moving the origin in the movie. 2Don't Zoom. Same reason, this video followed that rule. 3Include a clear and obvious calibration object. A meter stick would work, or even a Kobe Bryant (I can look up his height). Maybe it could be a Ford F-150 that has a known length. Something! 4Include the mass and height of all people involved. 5Use high…
Friction in Line Rider Is there friction in Line Rider? Does it function as physics would expect? To test this, I set up a simple track: ![Page 6 1](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/page-6-1…) Basically, a slope with a flat part to start with and to end with. Let me show you something simple before further analysis: ![Page 6 2](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/page-6-2…) This is the x-position vs. time for the line rider on the first horizontal portion of the track (before he or she goes down the incline). This shows the rider…