a few days ago, i put a plastic water bottle in the freezer, hoping that it would cool more rapidly than if i had put it in the fridge. accidentally, i ended up forgetting about it, and a few hours later when i opened the freezer, i witnessed an intriguing phenomenon. when i opened the fridge, i expected the water to be completely frozen, however to my surprise, it was still liquid. after taking the bottle out and placing it on the counter, something else completely unexpected happened; the wate
usually, when shot at, the average person would have neither the reaction time, nor the hair strength to deflect a bullet with a braid of his hair. the mere thought of such an impulse delivered to a bullet without crushing it or harming the hair seems to go against all physics, however for those of you who have seen the movie pootie tang, starring pootie tang, you know that pootie dont need no words, pootie dont need no music, and apparently pootie dont need no physics.
i thought because i started my bloggery with a prediction and outlook of the course, that i should end it all with an analysis of the year. my thoughts on Mr. Fullerton as a teacher are that he is great at explaining things, and teaching in general. the course is very difficult, and he makes it easier to handle. i also think independent units are a good thing, and that they should be continued. as for blogs, i definitely think writing can help cement understanding of physics concepts, however my
recently, ive been interested in space exploration. not so much exploring stuff, but specifically life aboard the international space station. As one can imagine, everyday tasks we think little about on earth can be pretty complicated without gravity. on earth, we dont have much expirience with surface tension because gravity tends to have far more of an affect on liquids. In space, however, the absence of gravity results in surface tension being much more noticeable, and extremely useful. becau
yesterday i opened the window in my room because it was particularly warm outside, and throughout the day as i entered and left my room, i would accidently slam my door, even though i was accelerating it to the same speed to close it as i usually do. as i got used to my now much easier to close door, i thought about possible explainations for this annoying phenomenon. i hypothesized that the culprit was my open window. i figured that when the window was closed, the shutting of my door was harder
have you ever wondered how your refrigerator gets things cold? i have. turns out, refrigerators use the same physics to cool things as air conditioners, dehumidifiers, and many other household devices. what happens is there is a compressor, two coils of tubing, and an aperture; all working together to make your beverages so damn frosty. if you listen to a refrigerator, what you probably hear is the compressor. the compressor uses electricity to create pressure in the external coil, letting it ex
last year with Mr. Powlin we made some simple water bottle rockets after the ap exam. as we designed and built, we had a basic understading of what our rockets were supposed to look like, but for the most part were in the dark as far as the technical physics behind it. this is what i hope to explain. the common expression "this isnt rocket science" may have you expecting long equations with foreign symbols, however simple rocketry in its essence is counterintuitively pretty simple. for the type
as i was browsing youtube the other day, i came across this video of a kid who had the unique talent of being able to throw a business card with extreme speed and precision. as i sat in awe of his skills, i began to ponder the mechanisms by which he is able to throw such a flimsy object at such high speeds. when the movie plays through a slow motion section, i am able to have a look at the nature of the cards trajectory. I think the reason he can perform this cool task is because he throws the c
i have a problem. every time i pick up a cat to let it fall to its death, it manages to turn around mid air and land square on its feet, even when im not giving it any initial rotational speed. the law of conservation of angular momentum says that the cat can not start rotating after i have dropped it, assuming it starts with no angular momentum at all. so how they do it? turns out, they actually bend themselves into a v shape in mid air, breaking their rotational axis in two. this lets them tur
i don't know if its a law, but as a kid I've always been told to walk on the right side of the road. whether we have adopted this because someone decided that people should have a dedicated side of the road to walk on, or for some other social reason, im here to tell you why its a good idea from a physics standpoint. at least here in america, where the cars drive on the right side as well, physics says that people are safer when they walk on the right. it all has to do with relative velocities.
I just read the blog post about the Faraday cage shoplifter, and felt inspired to talk about another use for faraday cages. in todays modern society, mostly everything is electronically operated. since a few years ago, this electronic wave has grown to include credit cards. some companies today put electronic tags in their cards so that one need only to swipe their purse or wallet in front of a sensor to pay for items at stores. unfortunately, hackers have managed to create a handheld device tha
one very dull free period today i was wondering if Mr. Fullerton had not gone into physics, what would be his profession? i found prison-hardened hardcore gangster rap artist to be the most probable of options.
highlighters can be useful in many situations, and when you highlight something, it is pretty surprising how bright they look. the other day i was wondering this exact thought, so i decided to look it up. when you see a color, the amount of light entering your eyes is usually the same as the amount of visible light of those frequencies the color reflects at you, however, with highlighter ink, this isn't the case. when you highlight something, apparently the color you see actually creates its own
if you were to ask an average physics student about graphene, he would probably tell you about its potential to be used for its structural properties, more specifically its unsurpassed strength to thickness ratio. However, graphene also has many unique and desireable electrical traits. Because graphene is extremely thin, relatively strong, and conductive, you can use sheets of it as plates for a capacitor. the advantageous thing about a graphene capacitor is that you can fit a lot of plate surfa
This being my first blog post, i feel obligated to comply with the requests of Mr. Fullerton, and share with my loyal readers some things about myself and my outlook toward physics c. To describe my background, i would say that i have a wide range of interests, a large portion of which are science related, including microelectronics, circuitry, optics, botany, and laser physics, and a small amount of computer sciences, though i am not very good at it. the main reason i am taking physics c is bec
so the other day i let my rabbit have free range of my room for a few hours as i was doing my webassign, and after a while the mouse i was using for my computer stopped working. i checked the plug, and to my confusion it was still plugged in. as i attempted to diagnose the problem i looked below my desk for a moment, finding my rabbit with a mouthful of copper and plastic. tasty. unfortunately he had not only chewed through my mouse cable, but also that of my webcam, among others. i got out m
I made the transition from regular to electric toothbrush a month or two ago, and aside from the noticeable improvement in my oral hygiene, I've been thinking about how the toothbrush charges. I understand the manufacturers motivation for not using exposed electrical contacts, as such a design may let water inside, however i found the alternative to be far more puzzling. when you want to charge it, conveniently, you only have to place it on the peg protruding from the base plugged into the wall.
there has been a large amount of misconception around this topic, a major contributor being the fact that people mix cornstarch and water and call it a non-newtonian fluid, when in fact it is only a colloid. colloids are not fluids, as they are heterogeneous, consisting of liquid and fine particle mix. they have changing viscosity because the particles cant flow away as fast as the liquid, and are bunched together as a pseudo solid. this is different from a non newtonian fluid because the fluid
have you ever tried forging currency? i know i have. turns out, its not as easy as it looks. paper money has many copy-resistant properties that people can use to distinguish real from fake money. one example of this is the ink used to print a portion of the bill. this ink is special because it changes color depending on the angle it is looked at. this is achieved by infusing the ink with microscopic prisms that have sides that reflect different wavelengths of light. they also have strips of pap
due to my procrastinativity, i now have to due all ten posts in one night. its getting quite bland. i feel like talking about computer screens, as it is what i have been staring at for the last hour. so i shall. most screens are lcd, or liquid crystal display. i dont really know why crystals are involved, but it makes me sound like i know what im talking about. in an lcd screen, there are hundreds and sometimes thousands of small boxes called pixels that make up an image. Typically, each pixel i
The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.
APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to firstname.lastname@example.org. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.