SOUND WAVES IN ORCH

WOW ITS LATE.  anyways this past week in orchestra we held a mini concert on camera for Jana Wang who is undergoing chemo in texas.  The concert made me think about the physics reading and the concept of waves.  When two violins play the same note, the peaks and troughs of the waves combine to make a wave of larger amplitude, thus making the sound louder.  When an entire orchestra plays, the sound is very loud, and most theaters have special ceilings designed to make the sound louder or clearer to the audience.  Once again, physics saves the day.

ukelele

So my two cousins came over for dinner the other day and they brought their ukelele's with them.  Of course they aren't too good because they are only ages 5 and 7, and have only been taking lessons for the last month or so.  But when I tried out their ukelele I noticed that the strings had to vibrate in order to make the sounds, much like all stringed instruments must.  So thats when I realized that the strings move in an up and down motion with a minute amplitude that decreases over time.  Although this isn't simple harmonic motion, it is still a real life example that appeared in the most recent week of my life.  Physics, once again, appears to be everywhere!

hot afternoon

It was a hot sunday afternoon, so I decided to go sit down on the couch and watch some tv with the fan on.  My fan turns out to have an oscillating feature even though it's really old, so I punched in that button and sat down and relaxed.  The fan blew air in a fairly wide arc, spreading the cool it throughout much of the room at a very quick pace.  Soon I was relieved of the heat of the afternoon.  I realized that this has a lot to do with the physics we are learning because it is related to oscillation and wave motion.  The fan follows a certain pattern and always returns to the same spot in the same amount of time.  If I were to graph the displacement vs time graph it would look like a cos graph with a medium amplitude.  

fluid dynamics

This weekend I saw one of those inflatable bouncing castles.  It was very cool because it has a lot to do with what we've been studying in physics.  The machine pumps air through the castle so that kids can go and bounce on it.  I noticed that when one kid jumped up and landed, a kid next to him would feel the air beneath his feet pushing up against him.  This all has to do with the fluid mechanics that we have been studying.  Since air is considered a fluid, it fills up the entire container (the castle).  Since they want kids to be able to jump on the castle they need to have some place that some of the air can pass through, otherwise the pressure would build up and the castle would explode!  Anyways, after i finish physics homework, i'm going to relieve some stress there.

swimming!

This weekend my uncle, aunty, and two little cousins came from Seattle to visit us.  On Saturday we all went to go to the beach where we swam, built sandcastles, and ate lunch.  In the water I realized that, when fully submerged, I felt practically weightless, much like astronauts do in space.  Then I remember how many astronauts do underwater training in order to simulate the conditions of space.  When under water, you don't feel any forces pulling or pushing you in any direction, except for waves that come crashing over you.  Then I remembered all about how we're learning about gravity and orbits, and the effect of gravity from other planets.  This also relates to how the moon's gravity affects the tides of the ocean.  Interestingly, I didn't feel any force pulling me up towards the moon.  Perhaps because it was so small compared to my mass, or simply because the Earth's pull was much much stronger on me.  Either way, it was a very educational and very fun trip to the beach.  

Torque

Today my uncle came over and tried to fix our door handle.  While I was helping him, he asked me to hold one of the screws in place so he could turn it using a screwdriver.  This immediately made me think about the force required to turn the nut.  T=r x F.  This was not the only time this weekend that I thought about torque.  In tennis when you hit the ball, you don't want your racket to unintentionally turn on impact otherwise you will mishit it.  This depends a lot on the torque of the ball on the racket, and vice versa.  

Family Dinner

So on Sunday night, my uncle, auntie, and two cousins came over for dinner. It was just an average, normal family dinner. But then I saw that my two cousins (both girls, 5 and 7 year's old) had a new toy with them. It was one of those barbie/fairy doll flying spinners, and instantly I thought "OH YEAH, physics blog" So to work these toys, a large amount of force is required to pull on a cord, which will cause the toy fairy to spin rapidly, and fly into the air. I realized that part of this motion involved centripetal acceleration and centripetal force, similar to the homework problems we have been doing in class. So anyways, I watched my cousins play with their toys after dinner and studied the motion of the toy after it launched. I noticed that this motion seemed like a parabola, and perhaps may deal with kinetic equations, except for the fact that the toy was spinning in the air. Maybe someday later I'll learn how that affects flight motion. (something like that picture up top, but in a barbie/toy model)

MOMENTUM

So today I went to the store and saw one of those click-clack ball sets on display, just like the one in the physics room.  I stayed there a while just playing with them, testing out different heights to see the effects on the motion.  The momentum of the ball being pulled up transfers to the balls that it hits.  If we look at the law of conservation of momentum, the ball at the end of the line should be moving up at the same velocity that the first ball came in with.  Because of this, the click clack balls can continue for a very long time.  I wanted to buy them but they were a bit expensive since they looked really fancy.  Oh well, maybe next year.

Another XC example cause i got nothing else

Well this weekend I had to run a meet at punahou, and boy was it fun.  Basically half of the course was a nice comfortable downhill, but there was this one part where it was just an extremely steep hill.  So I was just cruising along around the building during the race, at a pretty slow velocity (keeping my momentum steady), when suddenly I come across this hill.  As soon as I took my first two steps up that hill, I felt my entire body slow down.  My velocity was much lower than it had been just a few seconds ago, and so my change in momentum had been very great.  I climbed up that hill slowly but steadily, only to come across a longer but less steep incline.  Fortunately after that hill, there were many downhills which was when I could accelerate.  Well this weekend was fun with class day, and XC/tennis and everything.  I tried to relax as much as I could seeing as how we probably won't get another long break for a while.  

a BOW chika WOW WOW

hello cyberspace

so today my mom asked me to take the laundry from upstairs to the laundry room downstairs.  As I was walking I was thinking about how much work this all took, then all of a sudden it hit me: Physics Blog!  I easily could have thrown the clothes down our laundry chute, but seeing as how there were lots of clothes at the bottom, I decided not to.  So since W= F x deltaX, if I think of myself as using the same force to lift the basket in both methods, then technically, I"m doing the same work, seeing as how the clothes will end up in the laundry room either way.  Amazing how physics enters our lives in the most spectacular ways imaginable.  Thank God for physics.

TEST TOMORROW STUDY HARD!  

ORCHESTRA?!

Well seeing as how I've ran out of other topics, such as running and tennis, I've resorted to talking about orchestra, and playing the violin, and how that relates to physics.  Well, everyday in class our teacher tells us to warm up by stretching with our instruments.  We have to lift them up, left, right, and even twist them around to make sure we don't pull a muscle while we play (cause those hurt).  Sometimes our teacher will tell one of us that we don't play with enough power, and she will grab our bow and push down on it with extreme force, sending clouds of rosin into the air.  Let's see, what else...  Oh yeah, often times when playing fast music, the velocity of your fingers must be very high, yet constant, otherwise your timing will be off.  Shifting up and down the fingerboard also changes the displacement of your hand, but it can be difficult to make sure your displacement is a certain distance every time.  Although the movement of your fingers and your bow can be very minimal at times while playing the violin, it takes great accuracy and precision to master such an instrument.  All other instruments also require the same type of precision in order to be played well, which makes playing music such a wonderful joy (hahaha).

whatsup physics?!

Alright, so last week wasn't bad.  I didn't have any tests, just a bunch of quizzes, mostly physics.  Alright well this weekend, I ran a cross country meet, but I already used that as an example so I'll talk about tennis.  Today I played a tennis match (doubles), and in this tennis match I thought a lot about physics.  Just in a single point, the velocity of the ball was constantly changing.  My opponent would hit the ball hard, and when I hit the ball, providing more power, the velocity increased even more.  Not only was velocity changing, but the trajectory of the ball was always changing.  Sometimes there would be high lobs, where the ball would travel in a huge arc, and sometimes someone would just smack the ball, and it would seem like the ball had traveled in a straight line.  There were also a lot of different kinds of spins put in play, and i think thats related to physics, but we haven't covered that yet.  Anyways, when I was serving, I thought, how can i serve this ball really fast to the outside corner of the service box?  Well, swing hard, I thought, and aim toward that spot, using topspin.  Unfortunately, I missed, and the ball went into the net.  Too bad I can't be a computer and calculate everything I needed to place the ball perfectly every point.  I'm sure Roger Federer would be ownage at physics.

POST 2

Hi everyone,

so basically the physics test last week ate me alive.  But not as badly as the pch test did, hahahaha.  Well last week was brutal, there was a ton of homework from all my classes, and I had a test everyday from Tuesday.  The best part of physics this week was when we got to ride the elevator during class.  who knew so many people could fit inside that weinberg elevator!  I've never been in an elevator with that many people before, and it was interesting.  I thought it was cool how now we're starting to learn how physics applies to real life.  Lately we've just been doing examples like dropping a rock, or throwing a ball, and those don't seem quite as interesting when physics is related to other parts of life.  Anyways, lets see...how did physics apply to me this week...  well, on Saturday, us juniors had a bowling function, and i noticed that when I threw the ball with a greater force, it would knock the pins around more, causing more of them to fall, but when I threw the ball with little force, only a few would be knocked down. (either way, I hit gutter balls most of the time, fast or slow).  someday I hope to be able to calculate the exact velocity, spin, and force to hit a strike everytime!  Btw, I bowled a 110, not bad huh ;-)  haha jus kiddin.

FIRST POST

So basically in the first few weeks of school, physics has proved to be on of the more challenging courses.   I'm already behind on a couple night's of homework, so I have to go catch up on some of that.  Lets see... quizzes and tests are really fun! (and by fun i mean insanely hard).  I don't really know whether I like the online textbook or not.  It has a lot of pros and cons, but its definitely unique.  So lets see, what happened to me this week thats related to physics?  Well, in cross country, our coach was teaching us that if we increased our velocity (okay, he didn't use those exact words) just after turning a corner, and then went back to our normal pace, we could gain a good three to five meters over whoever was trailing us.  We had demonstrations, and it really works well! So next time I'll be sure to accelerate around those corners so I can put a greater displacement between me and the people behind me.

physics blog!!

Last week in precalc class our teacher helped us derive the famous kinematic equations, vcost=x, and y=vsint + gt^2/2. Deriving it using calculus really helped me review the basic concepts of projectile motion. He used an example of firing a canonball and trying to find out what angle it needs to be fired at, in order to pass through a point (200,10). Using the two kinematic equations above, any projectile motion can be solved. Math and physics are finally starting to make sense together!