This cool thing at a bubble drink store

So yesterday I went to ala moana to eat dinner with my family at Go Ma Tei, this ramen place that has good char siu tan tan ramen. Before we went to dinner, we went to go walk around and get some bubble drinks. While I was waiting for my honeydew bubble drink, I saw this cool see-saw propped on a stand with Santa on one side and a reindeer on the other side, and the first thing that came to my mind was torque! I know we did torque a while ago, but I had to write about this cool seesaw. Well, according to this particular seesaw, the reindeer is heavier because they are both sitting an equal distance from the fulcrum of the seesaw. Since torque is equal to distance from the fulcrum times force and the reindeer is exerting more counterclockwise torque, it has a larger mass and thus a greater weight. Physics is everywhere!

Surfing and Wiping out

I remembered to write a blog this week! This weekend was a good one. The only junk part was that I had to take the SAT. Other than that, I got to relax, catch up on sleep, and go surfing at Diamondhead. To tell you the truth, I'm horrible at surfing since ive only gone a couple times, but yesterday was awesome cause I actually caught like 5 waves!!! (I counted.) They weren't exactly big waves cause I'm not good enough to drop in on them but I caught some smaller ones. This was a lot more fun than the last last time when I borrowed my friend's shortboard and didnt catch anything. That time, I basically spent all my energy paddling out and then I was super tired so I couldn't paddle hard enough to catch any waves, and it was quite depressing cause I just kept getting pummelled by huge waves (to my standards) that I couldnt get out of the way of. Then, finally when we decided to go in, it was almost sunset. I was so tired and i was paddling so slow that it was dark by the time I got to shore. It was actually kind of scary, but yeah, theres my story about my horrible time with a shortboard. Never gonna do that again until I get better.

ANYWAY, I realized that there's a lot of physics in surfing. Since the surfboard was less dense than the water, the surfboard floats and this is due to the buoyancy force pushing the board upwards. Also, the concept of torque is important in surfing. There was one wave where I was too far up on the surfboard so I caught the wave but then I nosedived and drank a good amount of tasty salt water. Ok, so this was a pretty big wave so I was suppeerrr happy that I caught it but then that all changed when I was falling head first into the water. It was very sad and embarrassing and ahahah, Doc, you would've probably laughed at me. So from this experience, I learned that I gotta arrange myself more towards the back so my center of mass provides more counterclockwise torque to balance out the force from the wave. Standing on the board also causes torque. Force is also an important concept. The force of the waves toss me all over the place.

Oh, and here's just a taste of what happened to me yesterday when I couldn't get out of the wave's way. chee

Torque!

I couldn't think of anything to write about this time, but then as I took a popsicle out of the fridge, I remembered that I haven't written about torque yet. I gotta admit it was pretty hard to take balance the popsicle on my finger while i took a picture, but anyway, for me to balance the popsicle, the torque on the left side of my finger had to equal the torque on the right side of my finger. Thus, the popsicle would have a net torque of zero. Then, for an object to reach equilibrium, the net force in the y direction must also be 0. Uhh other than that, I don't really have much to say about torque. I was just watching the replay of the UH football game though, which we won 17-10 in overtime. The quarterback throwing the ball reminded me of projectile motion and all those equations, like V=Vot+1/2at^2. I hope i got that one right. Anyway, can't wait till Thanksgiving!

ThE pHySiCs In SoFtBaLL

Today, I played softball with my cousin, my brother, and their friends at ala wai park. We thought it was going to rain out, but luckily it cleared up, and it actually became a really nice day so we got to play. I haven't swung a bat since a couple years ago when I used to hit balls with my brother at the park, so I was a bit nervous, but it was all just for fun. At my first at-bat, I used this really heavy bat, so the bat controlled me more than I controlled the bat. It was actually pretty sad. But I managed to make contact with the ball and it went pretty far for my standards. This brings me to the topic of momentum, mass times velocity. I did not swing the bat that fast, but the mass of the bat made up for it, and I was still able to hit the softball pretty far. At my next at-bat, I used a light, yellow bat and I made good contact again, but this time, it went a lot farther. This was because although the mass of the bat decreased, I was able to swing harder and faster, so its momentum increased and resulted in me hitting it farther. Unfortunately, the ball never traveled as far as I thought when I made contact because the wind was going against the ball, which provided air resistance, which is a non-conservative force, and pushed the ball backwards. This collision between the ball and the baseball bat also brings up the topic of impulse, or the change in momentum. Before the collision, the ball is traveling at a certain momentum, but this momentum is changed after the collision. This is an example of an inelastic collision since some of the energy becomes sound. There are tons of other physics things in action like the force of gravity and stuff, but those things are too obvious to mention. Overall, it was a fun experience. Softball is really fun.

Centrifugal force (fictitious force)

Hello everyone hows everything going? I went to see the fall play on Friday night and it was pretty funny except I was a bit confused in the beginning. Kinda junk for me though too because I got there late, so I was sitting like in the second to the last row and it was a little hard to hear what the performers were saying. Anyway, my friend drove me home after the play, and on the way home I encountered physics. To get to my house, you have to drive around this wide loop, which is an exit on the freeway. My friend was driving towards the right pretty fast on the loop, which caused both of us to drift to the left in the car. At this moment, I remember reading in the book about how this is centrifugal force because it is experienced as an outward force away from the center of rotation. Technically, however, it's not really a force, so it is a fictitious force. So, if I were to draw a free body diagram of forces present, I would not draw a vector for centrifugal force. I remember this same force at the punahou carnival when I was riding the musical express or something like that and it was this ride that went really fast in circles. I remember i was sitting the farthest out from the center of the circle, and two people were sitting to the right of me. Holy smokes, it was the worst most painful, most not fun ride ever. Due to centrifugal force, I got crushed by the two other people (let's just say the two people sitting next to me were not light or skinny like me) sitting next to me everytime we took a sharp turn and I was gonna puke cause i kept banging into the bar and the wall of the seats. I've had bad experiences with centrifugal force. Here ends my story.

Yo-yos

During my elementary school years, I loved to play with yo-yos. I had the whole collection from the machine ones to those super long sleeping fat ones so that I could do as many tricks as I wanted to do without worrying that it will jump up and hit my face. I remember doing tricks such as walk the dog, eiffel tower, and around the world. Doing the "around the world" trick is an example of uniform circular motion if I kept swinging the yoyo in a circle around my head. The string provides the tension and is the centripetal force since it pulls the yoyo radially inward ( the term doc uses over and over again). Thus, Tsin(theta) is equal to (mv^2)/R, where m is the mass, v is the velocity, and R is the radius of the circle that I am creating when I swing the yo-yo. Also, weight also has an effect on the yoyo. The weight, mg, is equal to Tcos(theta), where T is equal to the tension and theta is the angle created by the string and my arm. Cool stuff.

collisions

This was a good weekend. Class day was fun, went to the beach, caught up on sleep, and ate a lot of food, but best of all, I got my fat boot off so i don't need my crutches. And for the record, Doc, I got my cast off on wednesday, went to class day, and I actually didn't screw up my ankle like you said i would hahaha. Anyway, this weekend my cousins from Washington came to visit and I got to hang out with my two nephews, Tyler and Tanner. They love cars and they especially like to play the ds game mario kart. They had their small collection of miniature race cars and we were pushing them around, when a two of them collided head-on and I thought, "Oh shnap! Elastic collisions and the conservation of momentum!" We were pushing them on a smooth wooden floor so there wasn't much friction but this is not quite an elastic collision because the total kinetic energy was not conserved. However, if I only include the two cars in the system, momentum is constant the collision is an action-reaction force with equal magnitude. The velocity of one is positive but the velocity of the other car is negative so the momentum and net force on the system is 0. We also played tons of mario kart and there were many two-dimensional collisions. These collisions happened super fast and they were in the game, so there is really no way to calculate the degrees and stuff. It's amazing how physics just pops up everyday!

Momentum in sports

I didn't get to do much this weekend because of my sprained ankle. I was bummed cause I couldn't go play a for fun game of softball with my cousins. BUT after learning about momentum, I noticed that it is evident in many sports including baseball and softball, volleyball, and tennis. In baseball, a batter like Prince Fielder with more mass can hit the ball farther because what determines how much force is applied to the baseball is the impulse during the split second that the baseball is hit. Impulse is the same as the change in momentum, and the momentum is mass times velocity so the more mass the batter has and the faster the players swings the bat, the farther the baseball will travel after contact. Also, in volleyball, hitters, if possible, take the farthest approach so that they can have more space to run and gain momentum before hitting the ball. The faster the velocity of the player, the more momentum, and thus, the player can hit the ball harder and with more force.

sprained ankles suck!...BUT i made doc laugh!

TWO sprained ankles in half a year. Ridiculous! Anyway, last thursday, I was at volleyball practice and we were practicing our triple blocking. I was blocking on the right side, so i had to go all the way to the left to block the left side. Ok, so our team isn't really that good at blocking so everyone was kinda drifting and it was pretty much all over the place. BUT i was the only one unlucky enough to land on someone else's foot, rolling my left ankle on the way down. My left ankle swelled up to the size of tennis ball, which was exactly what happened to my right foot just a couple months ago, so I guess one good thing is that both my ankles are now even in that both are messed up. But anyway, what I wanted to get to was that I finally made doc laugh! (even though I totally did not think it was funny). I dont think many people can say that they made doc laugh so I'm quite proud. This happened on Friday as I had to print out my paper and I now walk really slow so I was still getting my stuff together when period three already started. I was putting all my stuff into my bag in front of doc's period three class and all of a sudden, he just starts cracking up and i realized that he was laughing at me. I don't know what it was but I guess me being a cripple was pretty entertaining to him. Hahah so yeah thats my whole story about me making doc laugh.

Anyway, while I was all frustrated lying down, icing my tennis ball-sized ankle, I was watching my teammates scrimmage another team on Thursday, and I suddenly noticed how much physics occurs in volleyball. When the volleyball is put into play, gravity constantly affects the motion of the ball. Even when a player serves the ball, and goes into the air, gravity acts upon it at a constant acceleration. Air resistance is also in effect although there is an incredibly tiny amount because we were indoors. However, in beach volleyball, the wind and air resistance is a big factor as the path of the ball becomes increasingly hard to predict. Also, when a player sets the volleyball, it is a form of projectile motion as the player's hands apply a force to the ball and makes it travel to its destination. Forces are in effect the whole time as the players apply force to the volleyball when they spike it. Even in between points, when the players are just standing on the court, gravity is pushing down on them and a normal force going directly upwards is present. The grip between the volleyball players' shoes and the ground also causes friction so that they don't slip on the wooden gym floor. Finally, when a player goes up to spike the volleyball, they take a running start or an approach. This is a period of kinetic energy, but when the player jumps to hit the ball, this is transferred into potential energy as he or she goes up into the air. The higher a player jumps, the more potential energy the player has. So from spraining my ankle, I realized how much physics is involved with the sport of volleyball.

physics in tennis!

While playing tennis last weekend, I noticed that a great deal of physics is involved in the sport. It was quite windy on that particular day, so the motion of the tennis ball was constantly affected by air resistance, which we learned how to calculate in class. Personally, I don't like playing in the wind because it is a lot harder to control the ball and to hit the ball cleanly. Anyway, I also found that friction acts on the ball when it hits the ground, especially when there is a lot of backspin on the ball, causing it to stay lower on the ground. This leaves the ball on the ground for a longer amount of time as opposed to topspin, so there is more friction occurring when the ball has backspin. Also, constant forces are being applied when the racket hits the ball, and then the ball is at all times influenced by the force of gravity. Forces are not only acting on the tennis ball as the players are also influenced by outside forces. This would include weight, a force directing straight downwards, as well as a normal force, perpendicular to the ground directed upwards. Even friction is present when the players run as their shoes come in contact with the ground. Physics is everywhere!

skateboarding!

This weekend, I was doing some cleaning when I stumbled upon my cousin's old skateboard that he gave me. At first, I didn't remember why he gave it to me cause he was pretty into skateboarding at the time, but after riding it outside, I realized why. I went at most like 5 feet before I came to a complete stop. Ok, that's probably a huge exaggeration, but yeah the wheels were pretty junk. Anyway, when I was riding it, I realized that skateboarding was filled with physics concepts that we were learning in class including all of the forces acting on the skateboard including friction. The wheels on the skateboard were pretty fat, which meant that there was a greater amount of surface area touching the ground. Also, they were not smooth at all, which contributed to the high friction. It didn't help that I was trying to ride it on the gravel, but nonetheless, I did not travel very far although I would I would kick as hard as I could. A couple people were walking by when I was experimenting with my skateboard, and I didn't look but I'm pretty they sure laughing at me. Anyway, this takes me to another force: the force that I applied to the skateboard to make it travel. In addition, weight, which is my mass plus the skateboard's mass times gravity, was being applied directly downwards on the skateboard. Also, there was a normal force being applied perpendicular to the ground, which was equal to the weight of the skateboard and me. Therefore, there were four forces applied to the skateboard when I was riding it. Crazy stuff.

initial thoughts

Physics so far this year has been fun and interesting. I really enjoy the class, but it has been really challenging for me, and is by far the hardest science class that I've taken at 'Iolani. Physics class is also completely different from any of the other science classes in that most of the learning is done on your own. It took me a while to get used to this style of learning as opposed to chemistry and biology, where lectures were the core to learning about topics. In physics, the learning comes through figuring out the homework problems as well as the important labs that we have every week. The homework problems, especially the last few, have always proved to be very difficult, and sometimes I find myself going in circles and then my head starts to hurt. This is when I take a break for some ice cream or something. Anyway, I find that the labs are also very challenging and at times, frustrating, but are usually pretty enjoyable. I feel fortunate to have smart friends who can help me understand the concepts I have difficulty with. Most of all, I'm really worried about quizzes and tests because my scores have not been too great even though I've been putting forth my best effort and studying a lot. Even though I know that the course will only get harder, I am hoping that I can get used to the faster pace and understand concepts better since I dropped APUSH. I think it will be a cool year