energy
rallain | November 4, 2008**Pre Reqs:** [Work-Energy](http://scienceblogs.com/dotphysics/2008/10/basics-work-energy.php)
You need to be familiar with work and energy to understand this. If you are not familiar, look at the pre requisite link. Ok? Now, let's begin.
Suppose a ball moves from point A (3 m, 3 m) to B (1 m, 1 m) at a constant speed as shown in the diagram below:
Suppose there is some other force (like my hand) also exerting a force on this ball to make it move along this path at a constant speed. What is the work…
sheril | October 30, 2008Despite the economy, it appears some businesses continue booming. In July, we reported that Exxon Mobil posted a net income of $11.68 billion. Well, record broken. According to CNN, its third-quarter profit was $14.83 billion:
The latest quarter's net income equaled $1,865.69 per second, nearly $400 a second more than the prior mark.
So new quarter, same question: How about reinvesting some of the profits tax toward alternative energy research?
rallain | October 29, 2008I 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…
rallain | October 28, 2008Here is what is cool about [Fantastic Contraption](http://fantasticcontraption.com/) - it's like a whole new world, a world ready for exploring. I am Newton, and I can see if this world follows the models that I propose.
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…
rallain | October 20, 2008**Pre Reqs:** [What is a Force](http://scienceblogs.com/dotphysics/2008/09/basics-what-is-a-force.php)
[Previously, I talked about the momentum principle](http://scienceblogs.com/dotphysics/2008/10/basics-forces-and-the-moment…). 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.
Well, what is work? What is energy? How are they related? In [another post, I talked about energy.](http://…
sheril | October 7, 2008In my final post over at NexGen, I discuss how to conserve what we have. And while there are several layers, the most obvious begins with YOU.
Because the truth is that personal decisions matter. Really. And like all those bumper stickers read, 'Think Globally, Act Locally.'
Head over and read a few steps toward energy conservation I've outlined. Remember that the future is what we make it and a lot of people, doing a lot of small things, adds up to real change.
greengabbro | October 6, 2008A week ago, the USGS updated its official estimates of U.S. geothermal energy resources for the first time in over 30 years. During the past three decades, we've made significant progress on technology to exploit geothermal energy in areas where there's plenty of heat in the ground, but no natural hydrogeologic plumbing system to help us exploit it. In other words: We are much better at cracking rocks underground than we used to be.
Assuming that this type of rock-cracking technology (aka "enhanced" geothermal systems) continues to work out as well as expected, the new study estimates that…
j7uy5 | October 5, 2008
The photo shows the first commercial implementation of a
href="http://spectrum.ieee.org/oct08/6851">new kind of
solar-powered electrical generation station (source: IEEE
Spectrum).
The problem, of sorts, is that it is not in the USA. It is in
Spain.
The system uses parabolic reflectors to heat a kind of oil.
The oil is circulated through a system that runs steam
turbines to generate electricity. But, is uses only part of
the heat for that purpose. Some of the heat is stored in huge
tanks of molten salt.
A short video that shows the Andasol 1 station, and the manufacturing
of the…
rallain | October 4, 2008I think it is time for me to talk about energy. My ultimate goal is to give some insight into the many stories about perpetual motion. To do this, I will first talk about the fundamentals of energy.
**What is Energy**
I started thinking about this, and at first I realized that I did not have a good, short explanation of energy. The most commonly used definition in science text books is:
*Energy: the ability to do work (or something dreadfully vague like this).*
But what is work? It may be no surprise to find that many college level physics texts avoid defining energy. After some serious…
rallain | October 2, 2008Gas prices may be trending down, but they are still quite high. How can we save gas? One of my colleagues suggested we can save gas by getting rid of all drive throughs. This means it is my job to estimate how much could be saved.
**Starting Assumptions (estimations)**
How many drive-throughs are there in the U.S.A.? When I think of drive-throughs, I think of McDonalds. [Wikipedia](http://en.wikipedia.org/wiki/Mcdonalds) says there are 31,000 restaurants world wide. I am going to say there are around 20,000 in the U.S. that have drive-throughs. So then, how many total drive-throughs?…
rallain | October 2, 2008I was recently re-watching a MythBusters episode and I found something I had wanted to explore previously (but accidentally deleted the episode). Here is a short clip from the "shooting fish in a barrel" episode:
Did you see what I found interesting? That big barrel of water left the floor from being hit by a bullet.
The question here is: Does a bullet have enough energy to increase the gravitational potential energy of the barrel to that height?
First, let me gather some data. From the episode, the Mythbusters were firing a 9mm pistol round into the barrel. I don't know much about…
rallain | September 30, 2008Which 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…
sheril | September 28, 2008On September 25th, Nature magazine published 'Choosing A Future,' telling us more about where each presidential candidate stands on science related topics. And despite the humorous and uncanny similarities of the front and back covers, this is a very serious issue because it outlines some differences in their strategies. Not surprisingly, of particular interest to me are their positions on oil drilling which I've posted over at NexGen.
The gist:Obama: Don't expand domestic drilling and reduce dependence on oil altogether.McCain: Drill Baby Drill! and expand offshore-drilling.
The full…
sheril | September 23, 2008Over at NexGen, this week's question asks about the likelihood of embracing tidal power: a form of hydropower that converts the energy of tides into electricity. Basically, we're talking wind turbines located where there's strong tidal flow. Sounds clean, and heck, I sure do like the ocean... but uh, I just don't see this becoming a major contender in our alternative energy future.
My full post is now up outlining many reasons why...
sheril | September 18, 2008by Philip H.
DISCLAIMER - The opinions expressed in this blog post are those of the author alone. They do NOT represent the official opinion, policy, or action of any governmental agency the author may work for or have ever worked for at the county, state or federal level. If you do not like the content or opinions, contact the author, not your Congressmen.
In my last post for The Intersection, I let folks in on the potential energy and carbon savings from software that would automatically turn off computers across various federal executive departments. At the time, I also referenced a…
rallain | September 15, 2008There was this commercial on the radio about Trane heating and cooling units. The ad claimed that the units could use up to 50% less energy than your existing unit. This started me thinking (because before that I was in a complete state of non-thinking). Do you remember the Y2K problem? Basically, when people started writing programs back before Star Wars they had to be very conservative. The hardware of the time did not afford the programmers to have frivolous code. To conserve, they only used the last two digits to represent the year (1970 was represented as 70). Obviously this…
revere | September 15, 2008That anyone would think -- much less say -- as John McCain did of Governor Palin that she "knows more about energy than probably anyone else in the United States of America" means either McCain is one of the stupidest people in America (doubtful, since the competition is too strong); or that he doesn't mind talking bullshit if he thinks it will help him and he thinks most Americans are stupid. You choose. But surely Governor Palin must know the basic data about energy, given it is Alaska's main source of support. "Don't call me Shirley":
Challenged by [ABC's Charlie] Gibson on her "national…
rallain | September 14, 2008Friction 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:
Basically, a slope with a flat part to start with and to end with. Let me show you something simple before further analysis:
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…
j7uy5 | September 13, 2008As
href="http://scienceblogs.com/catdynamics/2008/09/nasa_views_ike.php">noted
on Dynamics of Cats, The Oil Drum
has some details about loss of production of oil, natural gas, and
refined oil products, due to hurricanes
href="http://www.theoildrum.com/node/4525">Ike andGustav.
(They've been updated since the link first went up, so you
might want to check them again.)
Perhaps more importantly, they also have a post that contains an
analysis of the implications for the supply of fuel (gasoline, diesel,
and jet fuel).
href="http://www.theoildrum.com/node/4526#more">Implications…
j7uy5 | September 10, 2008Probably everyone has seen it by now, but the NYT has a headline about
the "culture of ethical failure" at the Department of the Interior.
In a way it is not news; I, among others,
href="http://scienceblogs.com/corpuscallosum/2006/08/culture_of_corruption_part_ii.php">wrote
about it two years ago.
Back then, I referred to it as a culture of corruption. Now,
the
department’s inspector general, Earl E. Devaney, has expanded
that.
Instead of a culture of corruption, it is now a culture of complete
ethical failure. Corruption is only part of it.
href="http://www.nytimes.com/2008/09/…