The Physics of a Lazy Susan

Here we go: So this is the first time I'm doing my journal before nine o'clock at night on Sunday. Wow! I can't believe it. Real fast, that BJ Penn fight was just a huge smashing. GSP had superior position the entire fight and just worked him. It was pretty sad. At least Lyoto Machida had a good fight. That guy is scary. Anyway, I went to my friend's house to watch the fight and there was a lot of food. I mean a lot. The best was the pokes from Tamura's and the barbeque chicken. Ono. After the fight we didn't know what to do, so we decided to shoot a film. It was pretty stupid. The idea was to do a survival show. I was the survivorman. We just went outside on the street and did random stuff. I ate an aloe. That was sick. The whole movie was pretty stupid. Anyway that explains the fake dirt spots on my face. While my friend was doing the editing, I went to get something to drink. On the way back, I noticed that they had a lazy susan on the dining room table. It was pretty cool. I started to play with it. I put the soda cans on top of the lazy susan and spun it around. While I was doing this I was reminded of a lab that we did. The lazy susan was exhibiting rotational dynamics. I ran to grab the camera and quickly captured it on film. Here is what happened.

When I spin the lazy susan I am exherting a torque on it. That is, I am creating a force that causes rotation. This sends the susan spinning. The cans on top of the susan are sent into motion as well. Because they are spinning, the cans have both angular momentum and centripetal accleration. The can in the middle of the lazy susan is tricky. The can has a greater centripetal acceleration than can on the outside, but it has less angular momentum. Of course this makes sense. The two cans have the same linear velocity and moment of inertia. The can toward the outside has a greater angular momentum. The radial distance from the center of rotation causes it to have a greater momentum becasue the moment of inertia of the two cans are the same. This works oppositely with centripetal acceleration. The can on the inside is closer to the axis of rotation so its angular acceleration is greater. Because the two cans have the same mass, the centripetal force on the inside can is also greater. Centripetal force is a force that causes circular motion. Centripetal force is expressed similarly to Newton's second law. Fc = m*Ac The centripetal force always points inward. The pepsi can toward the outside of the lazy susan flies off of the table because the centripetal force is not great enough to overcome the force of friction which opposes it. Notice the can flies off of the suzan tangent to its circular motion.The can in the middle has a greater centripetal force and thus stays on the suzan. So there it is, physics on a lazy susan. I hope you get to play with one. Its super fun. Ok gotta watch 'The Office'. SeeeeYa SuckaTrucka!!!

The Physics of Wrestling II

Here we go: So I was having computer problems this weekend, and I was getting super mad. I think my computer has a virus. It kept randomly restarting. I was getting super angry. By nine o'clock I was flipping irate. I couldn't even listen to music to calm myself down. All of my music was on the computer. Grrr. I when it finally started working, I was looking through all of my files for anything suspicious looking and I came across these pictures of me wrestling. Some of these are from winter break, others are from last week. Because all I have been doing lately has been wrestling, I decided to use this on my physics journal. I rely heavily on takedowns when I wrestle. This is mostly because I suck on the ground. So one thing that we've been working on a lot is staying in good position at all times. Getting the takedown is all about being in a better position than your opponent. What I mean is, you need to stay in a good stance--ass down and head up. I realized that this is actually just simple phyisics, the concept of center of mass. The center of mass is simply a point (not neccessarily on the object) where an object's mass seems to be concentrated. You can also think of it as the balance point. You can calculate that center of mass by taking the sum of each mass times its position and dividing by the sum of all of the masses. The center of mass of a human is usually right below the belly button. The pictures above are of me wrestling in pretty good position. Both of our CMs are right over or behind our support bases. Because the opponents have their CMs right over their base, it is very hard for me to take them down. If I want to take them down, I need to extend their CM over their support base. Gravity will help create a torque, making it hard for them to stay on thier feet and easier for me to take them down. In the pictures below, you can clearly see me extend his body over his center of mass.

Here my legs are bent and my butt is underneath me. I'm in a pretty good position. If this guy was a lot stronger, I would want my head up more and looking into him. I would have to arch my back more also. This would cause my ass to sag even more, bringing my support base much wider underneath my center of mass and actually placing my CM behind the support. Here though, he isn't putting that much pressure with the wizzer. Notice, though, that my arms are extended. I'm a lot weaker in this position and its hard to hold up his leg. In the next picture below, I jack up his leg and pull it into my body. This makes me stronger and it extends his CM out over his support. Before you go on, take a look at the girl in the yellow shirt in the photo above. Then look at the guy in white sitting next to her. It looks like he's watching her adjust her bra. Sick.

In this picture, you can clearly see that my opponent is extended. His center of mass is clearly over his support base. He is weak in this position. I would also like to point out that I made a mistake here. Now I'm out of position also. You can see how I brought my hips in and under me. This would be good if I was trying to pick him up, but here I'm out of position. My CM isn't behind the support base anymore. If my legs are bent and my ass is down, I'm a lot stronger than when I'm standing straight up. Hey! My moment of Inertia increases, making it harder to turn me. Despite this, I'm still able to get the takedown. Two points. Yay!


P.S. This guy that I'm wrestling in these last three pictures was super duper stinky. Especially downstairs. Just ask Maxxx. He wrestled him too back in the day. I can't really describe the smell but it was pretty nuts, dude. Oh yeah, the ref in the first picture at the top looks like Mr. Feeney from Boy Meets World. Feeney Feeney Feeney

Getting my ass kicked, Ouch!

Here we go: So this is the first journal that I've written in months and months. Wowie Kablowie Man. That definitely cannot be good. So last time I randomly stuck pictures of WWE superstars into the journal; mostly just for funsies. This time I decided to stick with the WWE theme. Maybe next week I'll do some real wrestling. I have a few perfect moves that I could demonstrate. There is even a move called the "torque" Unfortunately Maxxx and all of the other wrestlers were in Maui and I had no one to do these moves on. So I was sitting at home trying to find something physics related that I could take a picture of. This weekend was pretty uneventful so this was proving to be quite a challenge. Today I did almost nothing. I stayed home, lifted, ran, and did homework. Boring. It turns out, something physics related literally jumped out at me. Earlier I had the last glass of milk while everyone else was out of the house. I didn't think that it was that big of a deal, but apparently it really pissed off my sister. So I was walking to the computer to do my English paper when, all of a sudden, she pounced. BAM! She hit a codebreaker out of nowhere. While I was on the ground cradling my throbbing visage, she immediately locked in the Walls of Jericho. I was so scared! I didn't even know that she could perform Chris Jericho's two devastating finishers. She kept yanking my legs up unrelentingly. Look at her bulging biceps. Look at the crazed expression plastered upon her face. Yikes! I thought my back was going to break! It was so painful. In fact, my back is still throbbing as I write this now. The pain will just not go away. I can tell you why it was so sore. My sister was applying a gargantuan amount of torque directly onto my back. You see the point of rotation is directly on my back, right where she is sitting. My legs are being yanked and yanked because these serve as the lever arm. Thankfully for me, my legs bend. If they didn't they would be snapped off. The reason is, my sister is actually applying a force almost parallel to my back. This all creates a massive torque. The torque is, as you can see, causing my legs to bend and rotate. What you can't see is that unlike my legs, my back doesn't really have any flexibility. It is actually bending a teensey bit upwards. Thus the pain. I tried my best to ignore the burning sensation, but in the end I was begging her to stop. I learned my lesson and I tapped out. I will never drink up the milk again.

Last Journal of the Quarter

Here we go: I would say that I am really frustrated in physics now. I feel the same way as Mr. Gene Snitsky. Look how ugly he looks; ugly and angry. Yikes! Anyway, at first I was just cruising through physics. Then I stopped doing homework for a while. I tell you sir, that was a bad decision. I kind of went into a funk and forgot to do my assignments. I had to scramble to turn in four of them right before the test. For a while it was all good, then I didn't really know how to do the coffee filter lab. Our group did not finish it, so I kind of just forgot about it. But, because I forgot about it, I ended up getting no points for two labs! That really brought my grade down. In a brief aside, I would like to note that even though this guy is known as the "Love Machine", Mr. Kohara is way more handsome. :) Yay for you, Mr. Kohara. This guy could probably eat me. If this guy pushed you, you would be pushing back on him (Newton's third law) but you might get stuck in his fattness. Back to the journal but. So because of this period of dumbness, I might have ruined my grade in physics. Hopefully, I can save it in the next three days. So anyway, I feel like Snitsky. Angry and mean. I would like to do this to someone. BATISTA BOMB!

Wrestling with Physics

Here we go: True dat, Javin. I concur. This was a pretty busy weekend. Today I went with Joey, Justin, and Erika to Fingers. Joey and I were there for over four hours! Yikes. So anyway, lets talk about the pictures. I am starting to get really amped up for wrestling season, and I wanted to do a wrestling themed entry. On Thursday after practice, a bunch of us stayed late to mess around. This, by the way, is also the same day that Maxxx got is fanny handed to him by our coach. So we were all extremely tired (just look at all of the sweat on oli fat-on-gia's shirt), but we decided to do some WWE moves. Nik Snitsky and I were going at it pretty hard. Suddenly, I said, "Whoa. This is physics". Unfortunately, I wasn't able to get any of the pictures and videos that we took from Keiko in time. Shucks. I'll save that for next week then. I promise. So anyway, the pictures that I am using now are from last wrestling season. This is a dual meet at Kamehameha, and I am wrestling the fro boy, Isaiah Fonoti. Wow, seeing these photos is really making me all agro right now. I can't wait to step back on that mat. The first photo is a perfect example of inertia. Think of Newton's first law. An object at rest will stay at rest, or an object in motion will stay in motion. Of course, if a net force comes and acts on this object, then everything is pooped up and the status of the object changes. Both Isaiah and I are pushing straight into one another. The force of me pushing into Fonoti is equal to the force that he is exerting onto me. As a result, we are both at rest. If you want to get technical, the force of the mat pushing up on us is also the same as the force of gravity. This keeps our feet stuck on the mat. In the second picture, I shot either a single leg or a high crotch (probably the high c) and I now control his leg. To do this, I had to exert a force greater than what was exerting on me to get him off balance. This net force breaks the equilibrium that we were in and gave me the opening to set up my shot. In the picture, we have established a new equilibrium. I have his leg, but it takes an incredible amount of effort to keep it. Not only is gravity pulling his leg down to the mat, he is also kicking his leg down with all his might and wizzering the sheeshee out of my shoulder. Because he is now exerting more force in order to free his leg, I must work that much harder simply to equal it. If I want to take him down, I have to give him even more force. Exerting all of that force tires you out super quickly. This guy weighs around 145, and all of his weigh is on my arms. Ouch! Sometimes physics is not phun.

Making Projectiles (sorry about the length, its funny but)

Here we go: So this week's blog was a son of a monkey to make. My whole Sunday got turned into one big poop thanks to this econ paper that I have been trying to finish. I've been sitting around all day trying to entertain myself and do the paper at the same time. I had to work last night, so I was left to do my journal all alone. Boo. Anyway, the paper made me super bored so I decided to entertain myself by making a really fun journal. My initial idea was to turn myself into a projectile by jumping off of my roof in a superman cape. Unfortunately, my camera isn't fast enough to get a good picture. Shucks. While I was on my roof, I spied my neighbor across the street watering his lemon tree/bush (I'm not sure what to call it because it is a really awkward size). This stimulated a brief period of reminiscing about my childhood. The story goes like this... So one day, my friend and I were bored. We were probably in sixth grade at the time (I know, bored sixth graders equals trouble). We got tired of shooting hoops and started throwing lemons from my neighbor's yard at each other. Our street is a dead end and makes a T with 18th avenue by the way. Our houses are near the top. Eventually we quit throwing lemons at each other and we decided to see who could throw the lemon the farthest. I played baseball at the time and I was confident that I would win. I reared back and let the lemon fly. It flew in a perfect parabolic pattern for quite a distance. Gravity was causing the vertical velocity vector to accelerate (at a rate of 9.8 m/s duh) downward. It could also pull at a rate of -16 ft/s according to Cropsey. We were watching intently to see where it would land, and all of a sudden... THUNK! A black Escalade comes zooming past the exact spot that the lemon is about to land, and the lemon strikes the car almost exactly in the middle of its roof. The car comes screeching to a halt, and we just book it out of there. That was pretty scary. So anyway, I'm sitting on my roof reminiscing about this moment when an idea hits me. I should create some projectiles for my physics journal. In honor of the sixth grade me, I used fruit. Just so you know, a projectile is anything that is dropped, shot, or thrown and than travels under the influence of gravity only. A projectile's velocity can be broken up into two vectors. A vector, by the way, is simply a quantity specified by both magnitude and direction. The first picture that you see is me dropping an apple off of my roof. I am not throwing it, so the horizontal velocity vector is zero. Gravity, though, is acting upon the vertical vector. As we all know, it is causing the apple to accelerate at speed of 9.8 m/s in the negative direction. If Maxxx actually reads this far, I will state-for his benefit-that, yes, I did eat the apple when I was done. It was quite tasty. The other picture is of me with the infamous lemons and a golf club. I am at the top of my street generating projectiles. Fun, Fun, Fun. Yes, I was aiming for the cars, but when you use a golf club the lemons just explode. The pieces go flying in all directions, and the juice gets everywhere (like in my eyes, Bachi huh). If the lemons did not explode, then they would exhibit a parabolic flight pattern. The horizontal velocity vector would remain unchanging. For the entire flight it would maintain the ultra high speed that it was hit at. If I had a stop watch and a meter stick, I could actually calculate this velocity with the formula: Change in X = Velocity times Time. All you need is the total displacement and the time in the air. The horizontal vector on the other hand is immediately acted upon by gravity once the lemon is hit. Gravity pulls at an acceleration of (-9.8 m/s). As the lemon continues to rise, its velocity decreases until it reaches zero. At this point, the lemon is at its maximum altitude. From there the velocity continues to decrease at a constant rate until it splats into the pavement or pegs an incoming motor vehicle with tremendous force. BOOM! Either scenario would result in a really big mess. I'm glad I didn't hit any cars this time. That would be potentially dangerous. Anyway, time to finish that paper. I've written more on this than on the paper. Yikes.

Sliding Down a Big Hill

Here we go: So this is a picture of my mom sliding down a hill on a snow tube. During spring break my family went on a trip to the Pacific Northwest. This was taken at the Cypress ski resort in Vancouver, Canada. Snow tubing is similar to sledding; all you do is slide down a hill. You can't really do tricks or anything, but you go pretty fast. At this moment, I am probably engaged in an extremely intense snowball fight with my sister (I'm winning of course). Any way, time for business. In order to generate any speed, you must first climb to the top or use the lift. When you slide down the hill, you end up back where you started from (the bottom). Thus, your total displacement is zero. Also, when you slide down the hill, you are displaying negative acceleration. This is a prime example of a person moving at a very high speed, but having negative acceleration. Even though my mom is actually gaining speed, her acceleration is negative because she is moving in the opposite direction.