It's over, so goodbye! :)

Well, it's been officially over since May 9th at around 4-ish pm. That was the moment when I finally finished the AP Physics B exam, the moment when my now Physics-free mind rejoiced, "Free at last! Free at last! Thank God Almighty, we are free at last!"


I felt it necessary to bring much needed closure to this portion of my life. So here I am.


I am not pursuing a science career so why did I choose to stick with AP Physics B? I could have dropped it. Well, actually, no, I couldn't have dropped the class because there were many reasons as to why I signed up for the class in the first place. And these reasons are the same reasons as to why I chose to continue with the class.


Reason #1: Advanced Placement Means Awesomeness
This is actually the shallowest and most "wow-how-very-overachiever-of-you" reason. I knew, from the very beginning, that I was gonna get a B in the class all year, AP or not, so why not take the extra 0.5 GPA boost? I'm not particularly strong in science (and math, either, since we're on this subject). I credit the grades that I get in both subjects to my ability to work hard when I have to work hard and to be able to follow directions. It's like baking. There are bakers who are artists, those who try new things and oh, maybe I should add a little bit of this, and maybe a little bit of that, and what they make definitely makes a statement. Then there are bakers who are direction-followers, those who faithfully stick to the recipe handed to them by the baker-artists. In math and science, I'm definitely a direction-follower. The teacher tells me this and that, and I don't question any of it. I do everything the same exact way that they tell me to do it (which is a bad thing sometimes, because not all problems that we are asked to solve are exactly like the ones in the textbook . . .). All year, the B reflected both my work and innate talent (my lack of it, actually) and I held onto it for dear life for the whole year. All for the extra boost.


Reason #2: My Sister Took the Class
Classic younger-sibling-reason. As a young naive freshman with an older sister who has literally paved the way for me since I started school, I can't help it when my science-minded parents tell me, "Take biology as a ninth grader so you can take an AP science course as a senior. Your sister's doing it." When you're handed the chance to prove that you are just as good as (maybe even better than) your older sibling, you take it. That way, you don't have to look for those chances yourself. But what I've learned over the years is to not get (too) upset when I don't live up to Shayne's accomplishments. When I was little, the goal was to be better than Shayne. As I got older, it became just to do equally as well. But now, the goal is to just try my best in everything I do (I really think that, by the way, I'm not just being self-righteous over here). Yes, I get a bit peeved when I don't do as well after Shayne, but I don't really mind because I have things of my own that Shayne hasn't even tried, so there. 


Reason #3: My Parents Told Me to Take It

Ignore the unsightly water marks. 

We're a family of nerds. My parents are nerds. That's where I get all my nerdyness from, actually, but we three kids are a bit different. While both of them are math and science nerds, I'm more of a word nerd. Shayne is an overall school nerd, I think. Josh is more sci-fi nerdy than any of us. And all three of us are pretty bookish ("bookish" is a great word). My mom is a Physics major, she used to be a Physics professor in the Philippines and she now teaches high school Physics. My dad has always been an electrical engineer, which involves a lot of Physics, too. One time, for my parents' birthdays (They have the SAME birthday! How cute is that?!?!), we ate at Romano's and we used the crayons that they give to the little kids to draw and write science/math equations on the table. My mom was writing out all the Greek letters used as variables in Physics. 


They know I'm far from the science stars they were when they were both my age. But they knew that I wasn't going to fail miserably either. So I could at least make them proud by not failing one of their favorite subjects in the world, right?


Reason #4: It Wouldn't Have Been the Same If I Hadn't Taken It

School is about challenging yourself and doing things you don't usually like doing because you realize later that although some things may not be super useful to you in real life, you actually gain so much that will help you survive it. The sleepless nights will come in handy when I'm up studying late for exams in college, the lab work with other people will come in handy when I have terrible co-workers (nervous and uncomfortable chuckle goes here), the patience, the blood, the sweat and the tears that have gone into this little bubble of physics in my life--they are NOT worthless. What doesn't kill you makes you stronger, right? Pain is weakness leaving the body, right? Physics was painful, and it certainly did not kill me. Therefore, I am stronger because I took the class.

BEFORE

AFTER (Get it? Like a STRONG magnetic field?)

In addition, our class bonded so much over homework cramming sessions during our lunch periods, frees, and after schools this whole year. We literally lived in the physics room. We may not have been doing physics stuff the whole time we were in there (hahahaha, all those physics toys), but just being in the general vicinity of the place and of each other made us feel like we were all fighting together, side by side. I have very fond memories in Mr. Heyler's room, yes I do. Junior year wouldn't have been the same without our physics bunch.

This has been a great year. Special and well-deserved thank you to Mr. Heyler for his bottomless patience with our antics, questions and for his Physics jokes!

Goodbye Physics blog, farewell to physics, adieu to all of you who have actually read this blog!

--Jen :)

Week 30: My mom's glasses

You know that irritating thing when you're wearing glasses and someone takes a picture of you so the camera flash causes this unsightly white spot on one or both of your lenses? I hate that.


My mom doesn't know that feeling because her glasses have an anti-reflective coating on them. This thin coating on the glass has a different index of refraction compared to the air above it and the glass below it. It decreases the amount of light reflected off of the surface. There is a wide spectrum of corrective lenses our there and sometimes, the thicknesses of the thin films may vary, or the indices of refraction could be different for multiple-layered lenses. However, these can change in order to cause destructive interference in the lens and lessen the burden on the eye.


Unfortunately, I do not have  picture of my mom's real glasses tonight but I do have this picture. 

She never has to worry about getting that unsightly white blot in her pictures. I, however, am not so lucky.


And, voila, the Physics of my mom's sunglasses.

Week 28: Class rings (!)

I'm a January baby, so I got a garnet on my class ring.

Last night, the class of 2012 received their long-awaited class rings. Because my last name starts with an R, I had to wait until about 10 or so rows of students (all with last names beginning with letters that precede R, of course) shook the hands of our class advisers and returned to their seats, clutching black ring boxes. 

When my name was called, I walked up to the front. Thankfully, I didn't trip (WIN!). I received my ring box and patiently waited (Another WIN!) until the moment before all juniors processed out of the chapel to take a small peek at my ring. 

And there it was. My first thought was of how the light reflecting off of the stone would be the perfect topic for my Physics blog this weekend (BEST WIN MOMENT OF THE NIGHT!). 

Light reflects off of the surface of the jewel at an angle equal to the angle of incidence, or the angle at which incident light hits the surface, according to the law of reflection. Because the jewel has many different facets due to its specific cut, it catches the light from different directions. Consequently, reflected light bounces off of the jewel in different directions, too. Reflection gives the jewel its luster.

At the same time, light is also refracted, or the light changes direction as it passes from air to the stone. Snell's law states that the product of the index of refraction and the sine of reflection of light traveling in the first medium is equal to the product of the index of refraction and the sine of reflection of light traveling in the second medium. This adds to the jewel's brilliance and luster.
I tried to take a picture of my ring to show how, when it catches the light at a certain angle, it scintillates more brightly than when it catches the light at any other angle.

And, voila, the Physics of class rings.

Week 26: Silly magnets (oooh...)

This week's jelly bean flavor was MAGNETISM (Ahhh...)


(Side Note 1: Am I the only one who hears an "oooh" or "ahhh" in the background every time someone says "magnetism" or "magnets"? No one else thinks that? Oh, okay, I guess I'm alone. Uh, thanks.)


So our refrigerator has magnets (oooh...) on it. Yup. 
And our family uses these magnets (ahhh...) to hang stuff: calendars, recipes and personal reminders;l sometimes it's pictures or personal reminders, maybe even my first and only 100% physics quiz (but it only stayed up there for a week).
I have a note posted up that reminds me (quite forcefully, might I add) to take my medication.

--No. I'm NOT crazy.
--The first sign of craziness is denial, dear.

(Side Note 2: 
--Readers: "Medication? For what, Jen?" 
--Jen: "Well, for the voices I hear in my head, of course." 
--Readers: "Ohhhh...")


Thanks to Physics, I can finally explain how these magnets (oooh...) stick to the refrigerator. 


On the atomic level, the electrons of the refrigerator's surface all have spins. The result is a magnetic domain. These atoms are like small tiny magnets (ahhh...) but the directions of their domains all cancel out because they're all randomly spinning in whatever direction they want 
(Side Note 3: Electrons are quite stubborn in this way. So stubborn.)


This results in no net magnetic field because the domains do not align.


However, enter typical kitchen magnet (oooh...). The kitchen magnet (ahhh...) causes the domains on the surface of the refrigerator to realign, thus creating a temporary magnet (ooh...) of the refrigerator's surface where the kitchen magnet sticks.


Lo and behold, it sticks. Yay. 


And, voila, the Physics of silly magnets (ahhh...).


P.S. Our family manages to buy magnets from places we visit, so here are some for your viewing pleasure.

Look at the cute penguin from Montreal, Canada!

Various magnets from Haleakala, Maui!

This one's from Barnes&Noble...not really a trip, but I really liked the quote. It's so...'Iolani, right?

Week 24: Dimming Up and Dimming Down

In the 2005 movie Bewitched with Nicole Kidman and Will Ferrell, there's a roll of different clips where Samantha settles into her new life. She moves into her new house and cleans it up, she has quite a bit of trouble setting up her TV, I think, and she even opens tons of cans of soda because she had always opened them by magic. Buy my favorite part of the montage is when Samantha discovers that her dining room lights have a dimmer switch and she has a bit of fun slowly making it brighter, then dimmer, then brighter and so on. And all the while she does this, she goes, "Dimming uuuupppppp....dimming doooowwwwwnnnn..."

That part always makes me smile.

We actually have a dimmer switch on the lights above our dining table.



"Undimmed"

Dimmed

 

The brightness of the lights depend on the power or the amount of current that flows through them. The higher the current, the higher the power and the brighter the lights. Therefore, moving the switch up and down changes the magnitude of flowing current.

But how does it do this? Inside the dimmer switch is a moving variable resistor. This is basically a piece of metal that can increase the distance that the charge has to travel.

As I move the switch up to dim the lights, the length (L) that the charge has to travel increases. The resistance of the metal (R), or the metal's ability to oppose the electric flow, increases as L increases.

As R increases, I decreases because the two are inversely proportional. As I decreases, power (P) decreases as well because the two are directly proportional.

Finally, as P decreases, the lights dim down.

And, voila, the Physics of "dimming uuuupppppp....dimming doooowwwwwnnnn...!"

Week 22: Big Daddy Battery Backup

"There's like a Baby [battery backup], and then there's a Mommy [battery backup], and then there's a big fat Daddy of a [battery backup], and that's the one you want." --JG, JR

<----- This is Big Daddy.

Big Daddy lives under my sister's bed (I share a room with her) and he provides us comfort. The two bottom plugs shown here are our laptop plugs. As you can see, our laptops are protected from any power surges because they are plugged at the bottom row.

We usually use the top row because Big Daddy would then not only provide us with much needed protection from power surges but also provide us with battery power in case of a power outage, thus shielding us from the horrors of the "OMG-I-CAN'T-BELIEVE-I-WAS-DUMB-ENOUGH-TO-TYPE-UP-MY-ENTIRE-'IOLANI-PAPER-THE-NIGHT-BEFORE-AND-NOW-THERE'S-NO-POWER-AND-I-HAVE-CLASS-FIRST-PERIOD-TOMORROW-WHAT-AM-I-GOING-TO-DO-I-CAN'T-SHOW-UP-TO-SCHOOL-WITHOUT-A-PAPER-TO-TURN-IN-I-AM-GOING-TO-DIE" scenario.

Big Daddy is the perfect example of electric potential, or voltage. Electric potential is the electric potential energy divided by the test charge. It is a reflection of the ability of electric fields to create electrci potential energy.

 

Big Daddy has an electric potential of 120 volts, as shown here. ------>

This means that it can be very dangerous (see the word CAUTION there in big letters?). And this is exactly why I had to turn it off and take off all the plugs before I felt safe enough to turn it over and take a picture.

To minimize risks to electric shock, plugs are always covered with an insulator, that is, an object where electrons do not flow freely; it can't conduct charge. It covers the metal pins that do conduct electricity. This way, the hands, when holding the plug, does not come into contact with the pins. If they do, however, a process called conduction would occur, in which electric charge would flow from the pins to the hands, causing an electric shock. Very dangerous.

And, voila, the Physics of Big Daddy batter backup.

Week 19: All-Nighter and his best friend, Mr. Thermos

This past week was super hectic what with finals and final papers and projects and a debate tournament all coming toward me like, in the words of the illustrious Dr. Webb, "a herd of angry hippopotami."

Hello, I'm Mr. Thermos.

So, like all 'Iolani students this week, I pulled all-nighter after all-nighter trying to cram everything that we've learned over the first semester. Wait, I mean, REVIEW. Right? Right, that's what we're telling people. We actually REVIEWED, not studied. 'Cause we should already know all of those concepts and whatnot. Emphasis on the should. Yeah. Um.

Okay, back on track here. The jellybean flavors of the week were 1) Temperature and Heat, 2) Kinetic Theory of Gases, 3) First Law of Thermodynamics, Gases and Engines, and 4) Second Law of Thermodynamics, Efficiency and Entropy. Yup--four chapters. *SIGH*

This ties in to my stressed spiel because an all-nighter's best friend is a thermos. A lovely, big fat thermos that can keep your coffee-slash-tea-slash-all-nighter-fuel all warm and mmmm-good.



Uber cool built-in thermometer



While the night is still young, I boil some water and fill up Mr. Thermos all the way up to the brim.

The uber cool built-in thermometer shows me the temperature is about 133 degrees F, which is 406.15 K. The volume of the water inside is 1.7 L or 0.0017 m^3.

As the night goes by, I keep adding fresh tea bags and refilling my cup (mmmmm....green tea with mixed berries) to stay awake. The thermos keeps the temperature fairly constant at 406.16 K. How?

Once I screw the lid on nice and tight, this is when the magic happens.

The water and the walls of the thermos exchange thermal energy because of the difference in their temperatures. But it shouldn't change much because the inner walls of the thermos should be made of something with a low specific heat. They reach thermal equilibrium and the temperature stays fairly constant throughout the night.

And, voila, the Physics of All-Nighter and his best friend, Mr. Thermos.

Week 16 : The 'Iolani Stage Bands

Unlike many of my AP Physics B peers, I do not play a musical instrument. Sadface!

But I'm not musically challenged or anything. Like everyone else who went to public elementary school, I played the recorder. I can kinda read music (Thank you, Ms. Komatsu!), I have a good sense of rhythm (I do love to dance) and I know the basics of playing the ukulele (But not like Scott Tan or Dardo--I merely DABBLE, but those two are uke beasts!).

So instead of playing music, I listen to music. I love my iPod and playlist-making is one of my hobbies (yes, I consider it a hobby).

The 'Iolani Stage Bands performed their Winter Concert at Aloha Tower Marketplace on Friday night. I went with my dad, primarily to watch my brother (he's a tenor sax man in Stage Band 1), but also to watch and support some friends, listen to music and, of course, discover the connections between the sweet sounds of the 'Iolani Stage Bands and the concepts that we're learning in Physics.

Sound is a longitudinal wave, which means that the motions of the particles are parallel to the direction of the wave. It originates from vibrations that come from the instruments and then travel through the air.

The Stage Bands performed songs that varied in speed, pitch and volume. In terms of waves, these are actually changes in speed, frequency of the sound wave, and the amplitude, respectively.

For changes in pitch, the frequency of the sound wave increases. At the same time, period (or the time it takes to complete one cycle) and wavelength (the distance between two corresponding parts of two waves) decrease.

For changes in amplitude, frequency stays the same (and so do period and wavelength) and the only thing that changes is the amplitude of the sound wave (or half the distance between the crest and the time axis, if graphed).

Here's a short video (which is mostly of my brother) of some of Stage Band 1's songs....

[Either my computer was just acting up, or Blogger Video Uploader is down--I can't upload straight through here, so I'm just gonna upload it on YouTube, then embed it here...]



And, voila, the Physics of the 'Iolani Stage Bands.

P.S. Great job to the AP Physics B'ers in Stage Band (I'm sure they couldn't stop thinking about Physics during the concert): Darwin, Scott M., and Max! :)

Week 15: El Escanciado

La semana pasada, investigué información sobre Asturias, una región de España.

Kidding. I won't write this blog post in Spanish. To translate that first sentence: Last week, I researched information about Asturias, a Spanish region.

For Spanish 3H, I had to make a presentation on a specific Spanish region and I chose Asturias, a region on the northeastern coast of Spanish. I had to look up the Asturian coat of arms and flag, learn about the region's main products, and explore the main tourist spots and activities that beautiful Asturias had to offer. I have to do my oral presentation this week. In Spanish, of course, so I'm crossing my fingers that I speak fluently.

But what does this have to do with Physics? Well, Week 15 of AP Physics B covered Fluid Mechanics. (Not very yummy, sorry).
 

One of the concepts we covered was fluid continuity and its matching equation. The concept basically states that at every point in a fluid, the rate of its volume flow rate is constant. The equation is shown here.

While doing some research on the Internet for my Spanish project, I learned that Asturias' traditional alcoholic drink is natural cider, or Asturian sidra. (Am I allowed to talk about this? If not, let's pretend that it's not alcoholic. It's sparkling cider.)

  

When it is served, sidra is poured a certain way, a specific method called El Escanciado. The server of the sidra, or el escanciador, has to hold the bottle horizontally high above his or her head and slowly pour it into the cup that he or she holds with the other hand down by the opposite hip. It sounds hard, doesn't it? It looks hard to do, too. But it's really cool. Apparently, pouring it like this improves the taste of the sidra. 

 

They have festivals for sidra!













As the sidra's flow gets closer to the cup, its cross-sectional area decreases. This means that the velocity increases as it gets closer to the cup because the volume flow rate has to be constant at every point throughout the fluid.

And this ultimately means that only the beastliest of escancidores can pour the sidra into the cup without spilling. Sidrerías, or unique bars that always serve sidra, usually have wooden floors because a lot of it ends up on the ground.

And, voila, the Physics of El Escanciado.

Here's a video:

http://dft.ba/-omgsidra

Week 13: True Love (!!!)

Physics can (supposedly) explain everything. But can it explain love??? Maybe not, but it can definitely explain attraction.

Roses!

To explain (gravitational) attraction, I turn to the cutest couple in my world: my parents. This also seems fitting seeing as we just celebrated my parents' anniversary on the 14th of November, a mere week ago. Ever since I was a little girl, I have always believed that no two people in the world could be more in love with each other than my mom and dad (awww!).

Newton's law of gravitation states that the attractive force of gravity between two particles is proportional to the product of their masses and inversely proportional to the square of the distance between them. (In this case, the two particles are my mom and dad--because, um, well, um, they're attracted to each other.)

Using the gravitational constant, the known masses of the two particles (i.e. my mom and dad), and the distance between the two, we can measure the (gravitational) attraction between the two (F-sub-G).

I literally had to take two pictures and put some distance between them just so I would have a magnitude for r because I don't have a picture of my mom and dad in which they at least have a foot between them--awww!)

And, voila, the Physics of love. I mean, attraction. Um, gravitational attraction.

P.S. My mom bought a new salad spinner this weekend and I was like, "Why couldn't you have bought this earlier, Mom?! This spinner is a more Physics blog-worthy topic than the Lazy Susan!" Haha. =D

Week 11: Lazy Susan

 Call me weird, but I've always had a special love for Lazy Susans ever since I was a little girl. When I was younger in the Philippines, we had a transparent one because the dining table had a glass surface with black metal legs. It was just, argh, I love them. They go round and round and round......

Unfortunately, I'm apparently a "big girl" now and, therefore, I am expected not to play with Lazy Susans anymore. But that doesn't stop me from taking (and editing) this short video of my mom's precious Lazy Susan at 10:30 on a Sunday night. When my parents were asleep.

I just grabbed a magnet from the refrigerator to illustrate the concept of unifrom circular motion as we discussed in Physics class (not a very tasty jelly bean, by the way, sorry). When the magnet is placed at the outer edge of the Lazy Susan, anyone can easily calculate its angular velocity and acceleration. However, when I place the magnet in the middle of the Lazy Susan, it does not have angluar velocity (because angle displacement is 0) nor a linear/tangential velocity (because its radius is now 0).


My family's Lazy Susan :)



Ooh, there's an eerie reflection hovering above it.



And, voila, the Physics of Lazy Susans.

P.S. HA! I just made it right on time! 12:00 right on the dot.

Week 9: That darn dent

I don't-slash-can't drive yet.

And I'm okay with that--I'm in no rush to get behind the wheel. Because I know that once I do, I would have to worry about drivers who do not stop to think about others. *cough*jerks*cough*

Exhibit A here serves two purposes for this blog:

1) It supports the view that I have stated above. 2) It shows us an example of momentum and its conservation in a collision.


Exhibit A



This dent, shown here, belongs to my father's Honda Accord. Fortunately, my father wasn't anywhere near his car at the time of collision. He parked the car at...um, I don't really remember where he was when this happened, so let's pick a place that men usually frequent...Home Depot? All right, so my dad parked his car at Home Depot, got out and went inside the store. After half an hour, he returned (carrying whatever he went in to buy), only to find that someone *cough*jerk*cough* had dented his car.

Momentum is the product of an object's mass and velocity. When two objects collide, the total momentum of the system is conserved.

My dad's car, with mass 907 kg, was stationary so its initial velocity was 0 m/s. Therefore, it had zero momentum. The inconsiderate driver may have been driving at 10 mph (4.4704 m/s--Is this the average speed limit in a parking lot? If it is, good. If not, let's just pretend that it is.) with a total mass of 1800 kg. After the collision, the two cars "join together" and move at the same speed So...how fast were the two cars moving after the collision?

My dad's Accord and the cuplrit's car were moving at 2.97 m/s. (-->)

This is an example of an inelastic collision because, while momentum was conserved, total kinetic energy was not. The total kinetic energy of the system decreased after the collision and the lost energy was probably converted to others forms--sound (I'm pretty sure that the collision caused some form of noise) and heat.

The dent on the car also shows the concept of impulse (J). Impulse, the change in momentum, is the product of force and time of the impact or collision. Impulse is constant because momentum is conserved. This means that if t increases, then F decreases. And if F increases, t decreases.

The dent in the car shows that the material "gave" or allowed for t to increase in order to lessen the force of the impact. If the car was made of a harder substance that does not easily dent, then the magnitude of the force would have been greater.

And that means more damage and more money. But that wouldn't be such a bad thing if, you know, all drivers were considerate. My dad wouldn't have had to pay for the repair all by himself (with the help of insurance, of course) if the inconsiderate driver had at least left him a note with an apology, and his/her name and number.

I mean, come on. If you know that you dented someone's car, how can you just drive away as if you didn't? That does not make any sense. And it probably never will make sense to me, even when I do start driving. I just know that I wouldn't be so inconsiderate.

And, voila, the Physics of that darn dent.

Week 7: Swinging the boredom away

For the past week or so, I've been dreaming about Physics. More specifically, about tension. I dreamt several times that, for some reason, I had to find the tension of some type of rope or string or I don't know what, but I just knew that I was supposed to find the tension and I was freaking out because I couldn't and, and, and....then I woke up. Is this what you call a Physics nightmare?

Ah, but on to more pressing matters: the jellybean flavor of the week!

This past week's new flavor--or flavors, actually, because there were three--were ENERGY, WORK, and POWER.

To illustrate these three concepts, I'm going to take a step back, leave ScienceWorld, hop over to NonScienceLand, and on to the foreign and fascinating country of Speech and Debate.

The Hawaii Speech League kinda-but-not-really-officially kicked-off the new season on Saturday, October 2, 2010 at Le Jardin Academy. It was the first debate tournament of the season.

Now, it is imperative that you understand that all speech and debate tournaments are NOTORIOUS for being late. For the past couple of years that I've been participating in the speech and debate circuit, I have never been to a tournament that ran right on schedule. Never. Ever. And this happens for many reasons, of course, but those don't really matter; just know that tournaments never really follow the schedule.

So, on that particular Saturday up at Le Jardin, after debating about nuclear weapons, offshore oil-drilling and US military presence around the world for three consecutive rounds, the tournament was, as usual, running late. The 'Iolani debaters found themselves extremely bored, to say the least, during the time period between the end of the third round and the awards assembly. While tournament officials tabulate and sort ballots and decide which teams won, the debaters wait. And wait. And wait. And wait.

Some debaters from another school were prepared--they brought playing cards. Some of us from 'Iolani brought homework (I brought Physics homework! ;P) but not enough to last the whole waiting period. So, with homework already done, we literally had NOTHING to do but talk to each other, eat, listen to our iPods, dance and lip sync as we listen to our iPods, sleep, and/or take pictures.

Then, we found something we are deprived of in 'Iolani: A SWING SET.

Don't they look like they're having so much fun? Well, maybe not Darwin--he looks scared.


First, all four debaters (from left to right: Zeke, Darwin, Josh, Ayami) did negative work as they pushed off of the ground to start swinging. The net force applied by the debaters went one way (toward the ground at an angle), but they moved backward in the opposite direction (toward the sky in the same angle).

As the debaters swung back and forth on the swing set, their individual total mechanical energies stayed constant. Each time they swung back to their highest point, they each had a certain magnitude of initial potential energy and zero initial kinetic energy. As they swung forward and reached their lowest point perpendicular to the ground, they had a magnitude of final kinetic energy that was equal to the magnitude of their initial potential energy while the final potential energy is zero.

At one point in the debaters' swing fest, Darwin got tired or something and he couldn't swing as high as the others were swinging (maybe he was scared to go that high, I don't know). So Josh actually had to get up and push him so he didn't feel so bad about himself.

Before Josh pushed him, Darwin had a certain magnitude of power. When Josh got up to push him forward, the net force applied on Darwin increased, therefore increasing work done and also increasing his power.

 

Josh: "Darwin, you're too heavy..."

Just for funsies, here are a couple more pics of the swing fest:

Darwin: Someone get me off this thing...help...

Several minutes later, we were called in for the awards assembly.

And, voila, the Physics of swinging the boredom away.

Week 5: Lovebirds and a peace sign

I literally just remembered five minutes ago that I had to make/write a new post for my Physics blog. Whew. I wouldn't want to miss a quiz grade (Hi Mr. Heyler!).

Lovebirds on the left, peace sign on the right.



Approximately one and a half seconds after I remembered, "Oh, french the llama, I'm supposed to do update my Phys blog!" my head automatically snapped to the calendar on my bulletin board (I guess I wanted to check that, yes, it was still Saturday and, yes, I still had time to do it). About half a second later, my eyes darted from the box marked "Saturday, September 25th" to the two hanging...things (What do you call these? Leis? Necklaces?)...on my board.

It took almost two seconds to see Physics in my daily life. And this is only the fifth week of school.

Uhhh...WOW. I will definitely notify you when I start thinking about Physics concepts nonstop.



Anyway, on to the jelly bean of the week! This week's flavor was: FORCE. Mmmm, yum.

Newton's First Law states that an object at rest stays at rest unless a force acts upon the object, thus causing it to accelerate. The net force of the...let's call it the "lovebirds" (It's too big to be a pendant!)...anyway, the net force of the lovebirds is zero because it is not moving. The same goes for the "peace sign."

For each "necklace" (Or is it more of a lei? No word exists to describe these things!) the force in the downward direction (mg) is equal to the tension of the string's upward force (T). Please see equation to the right.

Now, if I were to pull hard, vertically, on the strings, the downward forces (mg) increase and they become greater than the tensions of the strings (T). Net force would then be negative and in the downward direction. As a result, the lovebirds and peace sign fall towards the ground. But I wouldn't want to do that, of course. I'd have to pick them up (and who wants that, right?).

And, voila, the physics of lovebirds and a peace sign.

 

Hope everyone had a great time at Peace Week at 'Iolani this week! :)

Week 3: Throwing rocks and trying to kill seahorses.

LIES. Seahorses are my friends. But more on that later on in this post.

The jelly beans for the past two weeks have all tasted the same--very projectile motion-ish. It tasted a bit weird at first, but I got used to it.

I actually planned on writing about tennis for this post. But I ended up sleeping in on Sunday morning and my brother and my dad left to play tennis way before I woke up. But that's all right, because I'm making up for it with, not one but, TWO examples to illustrate projectile motion.

So onward!

For my brother's 14th birthday this past summer, we planned on going swimming at Hale Koa. But we spent a little bit too much time playing games at Dave and Buster's after lunch. Shayne (my older sister), Josh (my younger brother, a.k.a. the birthday celebrant of the day), my cousin Josh (yes, his name is Josh, too) and I got carried away with the games so much that by the time that we got to Hale Koa, it was already a bit chilly and we didn't really care much for freezing in the pool. We were supposed to meet our parents at Koko Cafe later on for dinner, so we needed to kill time. We ended up going for a walk along the beach until we reached the Rainbow Tower by the Hilton Lagoon. While my sister and I watched, brother-Josh and cousin-Josh began to "skip stones." But they weren't really skipping stones, just trying to out-throw each other with the rocks.

I don't think you can see the rocks. But you can see, by their stances and positions of their hands, 
that they were trying to throw the rocks super hard.

At one point, they almost hit a little kid playing in the water (not shown). This is an example of epic failure. This is also an example of projectile motion.

A projectile travels in a path shaped like a parabola. In this case, the rocks are the projectiles because their horizontal velocity stays constant while their vertical velocity accelerates due to gravity.

A mini soccer ball being tossed up in the air to hit the cute seahorses painted on the wall is also a projectile.

The ball is 1.395m above the ground and the seahorses are 2.425m above the ground. My brother is standing 0.805m from the wall. I bet I can find the velocity of the ball!

So the seahorses were being repeatedly hit by a mini soccer balls moving at 4.82 m/s.
I think. I'm pretty sure. Either way, poor little seahorsies.

And, voila, the Physics of "skipping stones" and killing seahorses.