My long due Basic Physics Tutorial!

Well, my profile details claim an interest in physics and mechanics...and I don't think I have made even 1 post on that topic. So...here goes.
Be warned...I am not very good at maths...nor drawing. Just try to make pictures in your head. Of course, if you can't, the fault lies with the poor author! :(

Topic 1--> Why is it easier to balance a Bicycle when it moves?

This is something that has forever intrigued me...since I learned how to ride a bike...and had my first fall....which was while stopping the dashed thing!

So here goes. Get your imagination hat...put it on...and read further

Imagine a stationary cycle, with "Yours Truly" seated on it. (I weigh more than 80 kilos). Now, if I tilt sideways even the tiniest bit, the centre of mass of the cycle no longer lies between the wheels...and whoops, the result is an unfortunate bala, smeared with dust/mud. After all, the tiny force that is now not aligned with the centre line of the cycle acts to increase the instability of the cycle, leading to a greater force which is not aligned...which increases it even more...and so on and so forth.

So how is a moving cycle different? After all, when you shift even slightly, surely your weight is not on the centre line of the bike, and the results should be similar. But it does not happen. Why?
Here is why. The rotating wheels have a rotary moment of inertia, which when you tilt them means that there are two more forces sitting around other than just your body weight.

Warning: Tech Data coming up. Skip if you do not want
Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path. This force is called the centripetal force which means "center seeking" force. The force has the magnitude as given below.
Now for the meat...how does this centripetal force come into picture for a bicycle? While the bicycle is perfectly straight...well, it does not. But when you tilt the dashed thing, what happens. Your rotating tyre is also tilting, which now means that the centripetal force, which was doing nothing very special, now suddenly is acting at an angle to the vertical.
This angle means that the centripetal force now has two components....one directed in the vertical direction. ie: towards the sky/ground. And the other, horizontal direction.
Now, vertical makes no difference to us. However the interesting thing about the horizontal component of this force is that it tends to push the weight back to the centre line, thereby keeping the cycle stable.

Now, I dont have a scanner, which lets me write out the equations as well as the figures, so I will save that for another day, but suffice to say, the words above are an (somewhat unclear) explanation of this rather nifty real world problem. I especially like it because this is one thing that I figured out for myself rather than learning from a book. The book gives the information faster, but learning it intuitively is sooo much more fun and enjoyable!

k...any other nifty physical problems...well if you have them, I would be more than glad to think of their solution...but remember, it took me three fruitless years before I actually came up with the above explanation for the cycle thing. So questions are welcome...Just do not expect good answers.

p.s: I have to acknowledge the input of http://hyperphysics.phy-astr.gsu.edu/HBASE/cf.html, for the middle portion of my post, as well as that equation. Their page is not half bad either! :)


Well, till the Zener diode, and how physics is a lot like magic!
Ta Ta.

Movie Review: And life in general

Well, Continuing on life in Kharagpur. First I start with a movie review. I just watched Karan Johar's latest movie, Kabhi Alwida Na Kehna (I hope I got the spelling right!). And what was the movie like...other than long!
Well...I wish I could appreciate these bollywood movies more...but K Johar is in a league of his own. I have read these byte sized reviews, so I thought I will have a go.
Boy A marries Girl B
Boy C marries Girl D

Girl B loves Boy C
Boy C loves Girl B

Unhappiness and an extramarital affair later, Girl B divorces Boy A...Boy C divorces Girl D.
Three Years later....Girl D meets Boy C in railway station...and they go on to live happily ever after.

This of course took about 3.5 hours! So verdict...leave this at the theatres...watching it will just make you want to throttle the director! Of course, this is my personal opinion...I know one or two people who liked the movie. Good for them!

As for the rest of life. With exams coming up, I should now be seriously studying...but it does not take a genius to realise I have been watching movies and not studying! However, slow and steady wins the race...and the last day or two has actually seen me open my books and blow the dust off them.
Now to philosophy...today I had a moment of epiphany. This is a bit long, so wait around! I usually hate having cold water baths....why? Maybe I dislike being cold, or its the feeling when the first sharp hit of cold water hits my back. At any rate...I dont like cold showers. But today, I applied some philosopy I read in Robin Hobb (Assasasin's Quest...dont remember the page). Basically, it said something about not using your prior expectations affect your reactions to current stimuli (The stimuli in the book was cold rain).
So I tried eliminating all thought of the desire for hot water. The fact of cold water was inescapable, so I decided to eliminate the idea of dislike for the sudden deluge of cold water...And what do you know; It worked! I could actually take the plunge (figuritively), and enjoy the experience. The cold water was not unpleasant or irritating...it just was as it ought to be...and my experience was unaffected by my past beliefs or baths!
I wonder if I could use the idea for the rest of my life...But a word of caution for those who want to use the above philosophy. When I turned off the shower, I was as cold as if all that philosophising was just a bunch of hot air (which I longed for dearly at the time!).
Well, more for my next post.
Till then,
Ta Ta.

Back Again

I guess, like the bad penny, I continue to turn up when least expected!
The last few weeks have seen my (usual) insufferable superiority complex dented pretty badly. I have always held the (completely without proof) belief of my own genius. Out here, however, I see chaps who are actually capable of beating me when I am having a good day. Thankfully, I always claim I am not competitive, and then sidestep these issues, but I fear that may not be a long term solution.
So far, my progress with academics has been minimal. Maybe I have been away from the academic groove, but I find it extremely hard to get back to studying with an exam focus. However, that is changing slowly, or rather being changed slowly by circs.
I did find some time to read another book though. This was "Surely you are Joking, Mr. Feynman", which is a collection of anecdotes of Feynman, told in the first person. Very readable, and explains his own view of life, which is very different from most people. Worth Reading.
Well, that should do it for now. Now that my clock is claiming 4:00 am, I think it is time to go to bed, even if it is only for a couple of hours. That is still better than no sleep at all!