Hyperactive

I had too much energy after my trumpet recital on Saturday (probably due to soda and sugar) so I decided to go tree climbing. However, my first few attempts resulted in a fall. Well, practice makes perfect and I eventually managed to sit on a tree branch a few feet above the ground. This is a demonstration of the Conservation of Total Mechanical Energy. When I am at the top of the tree, I have no kinetic energy and using the ground as zero potential energy, all my energy is potential. At the instant I hit the ground, I have zero potential energy as my height is zero, but since energy is conserved, all that potential energy is transformed into kinetic energy. When I hit the ground, I have no velocity and the height is zero, so I have no kinetic nor potential energy. So where did all that energy go? Well, as I was traveling through the air, some of the energy was lost to friction due to air resistance. When I hit the ground, my energy was transferred to the ground, which vibrated to absorb the impact. That energy later dissipated into the universe, increasing the entropy. Kudos to Victoria Kim for her photography.

Valve Action

We all know I love my trumpet. Here's a picture for those of you who don't know what it looks like. You should be ashamed of yourselves.


Well, one of the things that change the pitch on the trumpet are the valves (there are actually lots and lots of things but to write about all of them would take several books). These valves aren't just simple buttons. They are sophisticated mechanisms with various parts.

The most important thing in the valve is the spring, which makes the valve pop back up when depressed. According to Hooke's law, the negative distance that I push down on the valve multiplied by the spring constant is the spring force. Let's say the distance of depression is 0.02 meters and let the spring constant be k. So therefore

Fs=-k(-0.02 m)

According to Newton's second law, F=ma. So let's say m=0.05 kg and a=0.11 m/s^2. So...

(0.05 kg)(0.11 m/s^2)/(0.02 m)=k
k=0.28

Yay! I now have some more physics to impress my fellow peoples at YS. Go trumpets!
Note: My playing sadly did not improve from this.

Ohlalalalala

I got semi owned by that quiz the other day about the pendulum. And pendulums! Look! That peace thing was one. Albeit with two strings rather than one (technically it is one, but I like to think otherwise). Even though these things are challenging, they sure are a lot better than the liver I'm dealing with now in Bio. My hands are going to stink for awhile... Why are my eyes blue? It's unnerving... So I found this 'physics' in Chinese class as it was dangling down my shirt. I guess it was random... but it does demonstrate the concept of tension and the tension and the weight being equal. The string exerts tension upward while the weight of the peace exerts a force downward. Imagine if the tension was less. Then the peace would bounce around! Wooohhoooo! Uhhh... I banged my hand against a big piece of chocolate during containment today, now it has a bruise. Was that caused by the pushing of the chocolate against my hand? Or was it just my stupidity? We'll never know...

Today I was at Hamilton Library and I rode the elevator, which had insane acceleration. Right after the elevator started moving, I felt really light as the normal force increased. When it slowed to a stop, I felt really heavy as the normal force decreased. I thought about doing the free body diagram with my hands, but there was no one else in the elevator...

Pencils... As I was doing (catching up with last week) physics homework this afternoon, I thought about how the pencil writes. The amount of pressure put on the paper by the pencil multiplied by the coefficient of kinetic friction determines how dark the ink is. If the coefficient of friction was lower, I'd have to apply much more pressure on the pencil to get the graphite to rub off, possibly creating a hole. I love friction. Oh look! It's the problem set! I had great fun with that...

What Now?

I find AP physics to be really fun. It challenges me to think, and I really haven't been doing that since I gave up self studying calculus in seventh grade. Well, not knowing any trig back then didn't help. Sure, slaving over problem sets and orange problems late at night can be grueling, but it is a good diversion from the APUSH reading and CNF essays. Oh well. I expected that Doc would teach more than he does, but it seems fine. I really think that the previous science teachers *cough* Dr. Kuba *cough* basically took notes for us, gave us pointers for the exam, unfair advantages, etc. Anxieties? I suppose I have a bad habit of random procrastination, so if I end up missing a lot of problems in conjunction with APUSH reading, I'm pretty much screwed. I'm really excited about learning about more physics! And the picture is a pretty good representation of my mental state. I'll leave the interpretation up to the viewer. Credit: Victoria Kim