2008年1月21日月曜日

17


this week was the last week of the first semester/2nd quarter. Which means, for us seniors, the hardest part of the school is over and we just need to worry about keeping up with what we had been doing. this also means that i still need to pay attention to physics properties that occur in our daily lives. First of all, i found it interesting that when you hear radio or tv noise through a phone, you can clearly see the lag. this is clearly because the sound waves are transmitted as radiowaves for phones and that is not fast enough to make is lag-free. i am guessing that the farther you are away from the sender, the more lag it will be and that is physics right there.

2008年1月14日月曜日

#16


This week was quite intereting. First of all, regualr physics class had their projects and i was helping my friends out. It was interesting how they had to make a car out of mouse trap as their engine. They used their physics knowledge and debated what kind of car would be good. Many of them thought making the wheels frictionless would make the car go farther but i told them the car needs friction in order to even move. Also, many argued that the car should be as light as it could be. However, clay and i both told them it should have a good amount of mass so it has momemtum to keep it going. However, it couldnt be too heavy so that it cant move. I told them to calculate it out but they seemed like theyre just going to just guess and check how it works. I knew right away this is the difference between AP and regular classes. We AP students will definitely calculate it out to see which kind of cars would get maximum efficiency out of the mouse trap before we start building one. It was fun watching them make though.

2008年1月7日月曜日

journal #15


This weekend, when i went to my friend's house, we were talking about why potential energy is mgh. I told them that you could derive it by using G and M and R. Although it was quite a long time ago, i remembered many things like satelite and orbital motions. However, there was one thing that bothered me when we were talking about physics. That is, in regular physics class i heard they draw centripetal force on their free body diagram. I told them centripetal force is an imaginary force (net force) so you arent supposed to put it there. But it seems they are required to draw it out. I told them that if they did that in our class they would get 50 points off for tests/quizes. They also didnt seem to understand centrifugal force but since i already explained it to them and they got it back then, i didnt really want to explain it to them again.
Also, when we went to zippy's, my friend had 1 yen in his wallet. From chemistry experience, we floated it on water. That's when our physics knowledge came in handy to explain how that works. Because the weight of 1 yen coin is smaller than the FB force due to its area, the coin floats.

2007年12月10日月曜日

#14


This week we learned a lot about waves and there are waves all over the world. Not only speed waves, we encounter so many waves in our daily lives. For example, while i was microwaving, i thought about waves because its in fact microWAVE. As waves go through the food, it moves the particles and that makes the food warm up (isnt that right, doc?). We also use waves to transmit the radiowaves and so on. But those are all invisible waves so we dont really notice them around. We notice more of ocean waves and stuff. Waves at the beach is the most commonly known example of a wave. We like to go surf and bodyboard when theres a high amplitude. However, when it has high amplitudes and higher frequency, it is dangerous. If you arent good at swimming like i am and go beach on those days, you have made a fatal error. Waves are fearlful though depending on what kind, it is quite useful. some light waves are pretty dangerous too. Some of them can cause skin cancer. Waves are seriouslly all over the world without any exceptions. Its important to learn stuff like that, right doc?

2007年12月3日月曜日

#13


While i was spinning my pen around (because i was bored while filing out informations for my college apps), i noticed that there was a spring inside a pen (i knew it existed but i didnt really care back then). As i observed that spring, i began to learn the mechanics of it. I was impressed how clever they made that thing. As i was impressed, and before i even knew it, i started to wonder if i can figure out the spring constants and some mechanics that actually enables the pen to work. i designed a experiment just like the lab. Except i didnt have the exact weight for 5g~100g objects, i couldnt really do the same thing as a lab. As a matter of fact, i ruined a spring by putting too much weight on it. It was great how i couldnt really just that pen anymore but its alright because i actually was thinking about physics while i was playing around.

2007年11月26日月曜日

#12


This weekend was pretty awesome since it was four day weekend and there was barely any homework. It was pretty nice getting rest from everything once in a while. Therefore, i didnt really have anything physics related this weekend cuz i pretty much spent all my day at home just sitting around, doing nothing. But on saturday, i went out with my friends again to bryans (doc, you gotta come with us!). But since i already talked about physics of pool, im not going to. I actually want to talk about centripetal force and centrifugal force. while we were driving around, people in regular physics didnt know the difference between centrifugal and centripetal force. some of them even argued theyre the same thing. So i told them that centripetal force is the net force and centrifugal is the imaginary force that you feel. When we got to the curve, i told them there is radially inward acceleration and they nodded. And when everyone started to feel the push towards outside, i yelled "THIS IS CENTRIFUGAL FORCE!"
that was fun

2007年11月19日月曜日

#11


This weekend, i watched couple tv shows that dealt with water. One of them was mythbusters and what they were trying to do was to examine if all those ninja skills were actually possible in real life. They tried walking on water by using wooden panels. The point of that is to increase the volume and area of the object touching water proportional to the mass so it would have higher FB's. It sounds very reasonable and it sounds like it works using the wooden slippers because woods has not that much of a mass but can provide a good volume. However, the plan totally failed because the mass of a human being was too much for that FB created by wooden panels. Perhaps if it had a greater volume then maybe it could work out. So they used styrofoam and made a big shoes out of it. The volume of that shoes was apporoximately .9m cubed or something close to it. Im not sure the exact value but from my estimate, thats the volume. So the guy had totaly of 1.8m cubed as a volume for 2 shoes. And the plan was a success because the volume provided more FB force than the weight.