Go Back Refinement of Mean Free Path The intuitive development of the mean free path expression suffers from a significant flaw - it assumes that the "target" molecules are at rest when in fact they have a high average velocity. What is needed is the average relative velocity, and the calculation of that velocity from the molecular speed distribution yields the result which revises the expression for the effective volume swept out in time t The resulting mean free path is The number of molecules per unit volume can be determined from Avogadro's number and the ideal gas lawleading to It should be noted that this expression for the mean free path of molecules treats them as hard spheres, whereas real molecules are not. For noble gases, the collisions are probably close to being perfectly elasticso the hard sphere approximation is probably a good one. But real molecules may have a dipole moment and have significant electrical interaction as they approach each other.
Over the course of thirteen stories, Tan unpacks the ways intimacy with a place, person, or idea can be at once comforting and alienating. Tan spent the majority of her childhood in Singapore, and while most of the stories take place there, the settings range from an American college town to a magical kingdom infested by dragons to a colony on the moon.
Inez spoke with MQR via email; the conversation has been lightly edited for length and clarity. So first off, congratulations! And hopefully, the rankings mean that more people will get to hear about it. All of these stories are, in one way or another, about home, and the nuances of what it means to call a place home.
As a writer, what does it mean to write about home, and more generally, about place? I wanted a title that most people from Singapore would recognize. That was my way into writing about Singapore, and still is my relationship to it.
That was what happened for me with this book. Also, I love the moon. I was relying on what I could remember. That all made perfect sense to me, but as I wrote the story I realized how strange it was, at the same time, to someone looking in from the outside, this American fast food chain that was also such a part of growing up in that part of Singapore.
Who you were there, and who you were with? Did that distance help you? Do you think we need to be away from home to write about it? So did having the constraint of memory, once I started viewing that as something I could work with. I placed him in a suburban neighborhood that I remembered from visiting a friend who lived there more than ten years ago.
But sitting in my apartment in Michigan, I realized instead that I could make what I knew work for the story. Jim Shepard was my thesis adviser at Williams, and he used to draw these faint little diagrams in pencil on my stories. I think it is, but I do wonder. I think when you try to love something more, when you try to know it better, you have to see it more clearly, with all its beauty and its pain.
I love realizing that the lyrics to a pop song are actually devastating. You just referenced two of my favorite stories in the collection: This question is a two parter: How did that come through in the story, if at all?
Basically, that story has two acts.
In the first, Cheryl, a middle school social studies teacher, discovers that her students have a running joke: The second part of the story is what Cheryl does about it. Figuring out what that was was what the story had to do in me.
Cheryl was born the day Lee Kuan Yew died. It was a little surreal to revise the story to include the exact date, after it happened: I was born inthe year he stepped down as Prime Minister.
He immediately took up the post of Senior Minister, and remained active in the government for many more years, but his biggest achievements were far enough in the past that I was learning about them as history in school.
Both Cheryl and I have the sense that the world we live in was completely shaped by his legacy, in good ways and bad, materially and intangibly.
But that kind of progress comes with its own baggage. As a result, Cheryl has a humorous exterior, but a hard-headed, deeply pragmatic core that I hope is a little heartbreaking by the end. That story also stands out to me in part because, shortly after you workshopped it at Michigan, the real Lee Kuan Yu passed away.
On a lighter note, it was just fun writing in sci-fi elements like the flying food service robots, and figuring out why middle school girls would still need to take Social Studies in a future where they could just get bionic feeds implanted in their heads spoiler: What inspired that story and that choice of narrator?
My mom gave me a bag of dried oysters to take back to Michigan, and they went moldy in my fridge because I was too lazy to cook them.The mean free path is then the average length of a great many free paths either made by an ensemble of molecules or a single molecule followed for a long time, it being a .
The mean free path or average distance between collisions for a gas molecule may be estimated from kinetic theory. Serway's approach is a good visualization - if the molecules have diameter d, then the effective cross-section for collision can be modeled by using a circle of diameter 2d to represent.
Kinetic Theory of Gases Page gas can be understood by applying Newton's law to the microscopic motion of the molecules making up the gas and that a comparison between the Newtonian prediction and the ideal gas A related quantity is the average distance a molecule travels between collisions or the mean free path.
The distance covered by the molecules between two successive collisions is known as free path and mean of all free path is known as mean free path.
The number of collision per unit volume in a gas remains constant. In physics, the mean free path is the average distance traveled by a moving particle (such as an atom, a molecule, a photon) between successive impacts (collisions), which modify its direction or energy or other particle properties.
0%2) (mean free path in gas of identical molecules) (Note that a symbol in Rs Using these two probability densities write out two different, but equivalent expressions for the mean value of v2, where v2 = v x 2 + v y 2 + v z 2. Make sure the limits on the integrals are clearly.