Playing with my Food...

Tonight, I went to dinner with my family. I was sitting around, not really being social when I realized that some of the food in front of me had hidden concepts of physics.

This is my dad's plate after he went to the salad bar. "Here, I got you some, Steph," was the first thing he said when he came back, balancing this plate precariously on his hand while rushing back to the table. I laughed. I love my dad. :)

Anyway, I thought that balancing this much food would take a lot of skill. My dad probably wasn't thinking about Physics while raiding the salad bar, but there is obviously Physics here.

The center of mass of the food would have to be somewhere over the plate so that the food doesn't fall. It's even a little harder than that because we wouldn't want little pieces of mac salad falling off, would we?


This is the stack of bread that the waitress brought out for us. The first thing I thought of was how far I could make it extend over the top of the table before it falls were the slices uniform (I'm not even kidding, people...-__-).

I estimated that each slice was about 14 cm long. since there are 5 pieces of bread, they would be able to extend 11.8 cm out before falling.

7+3.5+1.75+0.875+0.4373 = 11.8

Well, there you have it, I'm obviously a Physics nerd if this is what I think about when I should be eating. According to my mom, I tend to think of blog topics while I'm eating. What does that say about me...? I wonder...

Oh, and I just thought I'd mention, HAPPY HOLIDAYS EVERYONE! :D

Falling Dollies?!

I have always been a pretty easily entertained person. When I was little, one of my favorite toys was probably one of those Russian dolls that comes back up when you push it over. It wasn't until recently that I discovered the underlying physics in it. There are two concepts that can be applied here: a stable equilibrium and (somewhat) oscillating motion.



There's my doll thingy. It's equilibrium is when it's standing straight up. I removed it from equilibrium by pushing it over. When I let go, it didn't travel away from equilibrium, but towards it. It took a little while, but it eventually ended up standing again. This demonstrates a stable equilibrium.

It shows oscillating motion because it goes back and forth. And if you were to graph it, it would look like a cosine graph. Haha.

There is more weight in the butt of the doll, which is what makes it go back to equilibrium. The center of mass/gravity is closer to the ground. Also in the butt end of the doll is a bell. I honestly don't know how my parents dealt with that thing. I could barely stand it long enough to take decent pictures. (Speaking of pictures, sorry they're not very nice. My photography skills are in short supply this weekend.)

Bendy Strawsss!

Pressureeeeee! It's everywhereeeeee! Like in my bendy straw. Haha.

Okay, so today I got mad at my dad. I failed my road test on Friday (more pressure! Like in the book!) and my parents wanted me to keep driving. I didn't want to, so my dad literally dragged me out of the house, threw me in the driver's seat, and made me drive (Sorry, people, a little venting/back story here).

Then my daddy bought me apple juice and Lifesavers Gummies, and I was happy again (I know, easily entertained child). I drove back home and wanted to drink my juice, so I found myself a straw. It was bendy which made me even happier.

I was also pondering a Physics blog idea. I started drinking from my awesome red straw when I realized that I was hardly getting any juice! It made me a little sad on the inside when I figured out that there was a hole in my straw. -__-
That's me drinking from my fail straw. Little did I know that I had a Physics topic on my hands. By "sucking" the straw, I was lowering the pressure inside the straw (or I would have if there were no hole!!!). Since the pressure outside is greater, the liquid travels up the straw. Since there was a hole, air got in the straw through it, so not as much juice came up, which means less juice for me. :[ So in the end, I just said, forget the straw and threw it away.

I guess this is another quite lame blog. Sorry. I should think of these further in advance...

Falling Phones and Physics

Alright faithful readers of my blog, sorry, but here goes another lame blog!

I don't really know when we were talking about it, but one day, Tulga and I were looking at our phones. This is my huge SideKick Slide:
Sorry about the bad picture, but it was taken off my webcam. Give me some slack! Anyways, my phone is very big compared to Tulga's awesome tiny phone:

Yeah, I stole that picture off his blog. Haha (FORGIVE ME TULGA!). We were standing so Tulga commented that if we dropped our phones, mine would hit the ground faster only because I'm shorter. It got me thinking about Physics and how we learned that no matter how different two objects are, when you drop them from the same height, they'll both hit the ground at the same time! So if Tulga were to crouch down a little so that his phone would be at the same height as mine, and if we both happened to drop out phones at the exact same time, they would both hit the ground (and break) at the same time (even though my phone is like 3 times Tulga's). Haha.

This reminds me of the time when I was playing with my friend, Tommy's, phone and I dropped it and caught it while it was falling. He probably would have killed me if i hurt his precious LG Shine. That was rather unrelated to the rest of this blog, I just felt I needed to take the opportunity to brag about my ninja moment.

Again, sorry about the lame blog. I'll try and do better next time!

When one door opens...

It's all because of torque! YAY!

I learned at a young age that you can't push a door open near the hinge. You see, my mom would always have to unlock the door, so she stood in front of the end furthest away from the hinge where the lock was located. And I, being the impatient little kid I was, would always try to push the door open from the only other end available: the one near the hinge. Sadly, every time I tried, my little hands and body was never able to open it. (Though sometimes I would push with my mom and pretend that it was all me. Hehehe.)

In addition, today, my dad was carrying our new TV into the house. Somehow he got himself in the door, but he was holding the door open with his head and couldn't move without the door closing on him. After laughing for a little bit (haha), I went to push the door open to help. I was carrying stuff too, so I tried to use my foot. I was too close to the hinge, so the door didn't budge and Daddy was still struggling. Instead of pushing it open, I used my butt to hold it open so he could get inside with no damage.

My difficulty with doors through the years was because of torque. Torque equal radius times the force. With a shorter distance from the pivot point, you need more force to achieve the same torque. I didn't know that as a kid, but now I do.
Yeah. That's my door (Ignore the dust >_<). I stood closest to my broken doorbell, which was not very smart of Little Steph. Luckily I learned eventually.

Today, I also realized that my doorknob is related to this same concept. I won't expand too much on this one, but you can have a picture. I'm sure you get the point by now.

Oh, but if you look carefully in the background, you can see my internet antenna from last week's blog! MIND BLOWING, isn't it?! :D

If This Thing Falls...O_O

Recently, we have been having some trouble with our internet. To fix our problem, my dad told us to put our antenna thingy way up high so that it might have a a better chance of picking up a signal. My mom heard this and took it to an extreme...This is the result...

The antennae is now precariously perched on a plastic thing which is on a stack of CD's which is on some black thing which is on my dad's computer which is on my dad's desk (Ignore the mess). In all, this antenna is about 5 feet up there which equals about 1.5 meters.

This thing has a lot of potential energy (Okay well not a lot, but I think it has a lot because there's a high chance of falling...>_O). I'd say that thing weighs about 250 grams which is .25 kilograms. So, since potential energy equals mgh, (.25)(1.5)(9.8), the potential energy of this antenna is 3.675 Joules. Okay, it's really not that much. Haha. Fail me.

If this thing were to fall, it would have kinetic energy, which is a different story, and I would rather not go there...First of all, my parents would probably get mad if I pushed the antenna over, and second, I'd be mad because then I wouldn't have internet. :]

Sorry about the super lame post. I promise a better one for next week!

WHEEEE!

This weekend, my mom made me go driving pretty much everywhere we needed to go. Naturally, being a girl, I have a bag that I take with me. So I put that and my water bottle on the floor on the passenger side as shown below.


I drove my family to lunch, forgetting about my bag, and when I got to the restaurant, my bag looked like this.

My poor bag fell over! And my water bottle was gone! Some of the things in my bag were even gone! I freaked out until I remembered what we learned about fictitious force in the textbook (okay, I didn't really freak out...). After realizing what probably happened, I looked in the back seat for my stuff.

There was all my stuff! My water bottle, stress ball, Chapstick, and hand sanitizer. I have no clue where the $5 bill came from, but it's mine now. >:D

There it is, people, Physics in action! The book stresses sooooo much that there is NO force actually acting on my stuff in the car. It's the the frame in which you view it! Hence the name, fictitious force. :]

In Honor of Halloween...

...I'm doing a semi-Halloween-ish blog this week! Remember those toys called Crazy Bones? The plastic things that were in the shape of crazy things that you slid across the floor to hit the other persons'? Well, if you don't, they're pretty much like bowling, but both sides have pins and you use the pins to knock the other's stuff down...Okay, that was a terrible description. Haha. Anyway, I remembered these toys and decided to go find them. I found a vampire one and a Jack-O-Lantern one, so I used those. The vampire is (very badly) colored black, and the Jack-O-Lantern is (equally badly) colored orange.

I had my mom slide them on our wood floor and this is the result.Starting position.


And this is what happened. As we know, because of the law of conservation of momentum, (Mass of the Vampire)(Initial Velocity of the Vampire)+(Mass of the Jack-O-Lantern)(Initial Velocity of the Jack-O-Lantern)=(Mass of the Vampire)(Velocity of the Vampire after impact)+(Mass of the Jack-O-Lantern)(Velocity of Jack-O-Lantern after impact). The vampire toy stopped in the exact same place where the Jack-O-Lantern started, so we know that the initial velocity of the Jack-O-Lantern is zero and the final velocity of the vampire is zero.

Therefore, (Mass of the Vampire)(Initial Velocity of the Vampire)=(Mass of the Jack-O-Lantern)(Velocity of Jack-O-Lantern after impact)

I don't really know, masses or the velocity, so this is as far as I can take this. Happy homecoming week, everyone, and Happy Halloween! Think about my vampire and Jack-O-Lantern crazy bones while you're trick-or-treating next Saturday! By the way, Jack-O-Lantern is a huge pain in the butt to type repeatedly...Just fyi. :D

What I did this weekend...>_O

Yeah...As you can probably tell by this picture, this weekend wasn't a very good one for me. I was driving and this hideous mess happened...JUST KIDDING! Haha. I'd get murdered if this happened while I was behind the wheel. This is actually my mom's friend's car. He got into a little fender-bender with a couple other cars. Someone rear-ended him and pushed his car into the car in front while sitting in traffic. Fortunately, he was unscathed, and he still ended up going to work (talk about dedication!).

The front of this car demonstrates a concept straight out of the textbook. We learned that the fronts of cars are designed to crunch like that, in order to prolong the time of impact, even though this is just a tiny crunch, it still has the same concept. Momentum is mass times velocity. Net force equals change in momentum over change in time. If the time is increased, but the change in momentum stays the same, the net force decreases, thus lessening the force of impact when the driver feels it, which is kind of the point of the crunch-able front of cars.

Imagine what could have happened if cars didn't crunch like that! :O

Tension Between Siblings

For the past couple days, I've been freaking out about what to do for my blog entry this week. Nothing struck me until just about an hour ago at dinner.


As you can see, my headphone cords are uneven. They are purposely like this so that you can put in one side, and pull the other side around the back of your head to keep the cords out of the way more. (If you don't get what I'm saying, track me down at school one day and ask. Haha.) Anyway, in the picture, the side I have in my ear is the shorter side. However, this style of headphones is unfortunately harder to share.

At dinner, my sister and I were eating and listening to music. I found that the earphone in my ear fell out much more often than my sister's. It occurred to me that it was because I had the shorter end.

I then proceeded to imagine the problem from our text book with the monkey holding onto a piece of string, but the lengths on either side of the monkey's hand were uneven. Our job was to find out which string had the higher tension, and it ended up that the shorter side had more tension because the angle the string made with the horizontal was greater.

Now I can explain why my headphone fell out more than the one I gave my sister. Unfortunately, only my classmates would understand. My family just gave me blank stares and absent-mindedly nodded their heads while I babbled. :]

Volleyball Physics

Last weekend, I went to one of my sister's volleyball games. (She's the one standing closest to the net by the way.) Anyway, while I was in the bleachers, I was intensely thinking about a topic to make my blog on. It wasn't until halfway through the game that I realize there was physics happening right in front of me.

Everytime the ball was bumped into the air, it made a perfect parabola with its path. It stopped moving when it hit a certain point and came back down to another player's arms...or the floor. I knew that was because of gravity acting upon the ball. I got so excited that I started babbling about physics to my mom and dad who were trying to watch the game. When they told me to stop talking, I whipped out my camera and started taking pictures.

In the pictures above, I colored over the ball in bright green to make it more noticeable. If you look from left to right in the rows, you can see the ball's arc and its highest point, which happens in around the second picture. After that picture, the ball begins to come down.

My sister, who is at the net, sees that the ball is not going to make it over, judging by its arc, and jumps to tip it over in the last photo. Little did she know, she used physics in her volleyball game!




This is totally unrelated to volleyball, but I found it interesting. Lately, I've been seeing physics everywhere...Even while I'm driving. No, not in acceleration or anything, I see it is street signs as well...
The first thing I thought of when I saw this sign was...FREE BODY DIAGRAM. If you rotate it a little, it could totally pass for one, am I right? I freaked out when I saw it, and immediately told my mom to take a picture. Okay, it's a little bit of a stretch, but trust me, from now on, when you see one of these yellow street signs, you're going to see a free body diagram. Haha.

Free Fall Physics!

This past summer, my family and I went to Disney's California Adventure Park. While there, we rode many rides, including the Twilight Zone Tower of Terror. The Tower of Terror is based on an old movie in which a bolt of lightning strikes the Hollywood Tower hotel, causing the elevator to malfunction and fall, killing whoever was inside of it.

This attraction takes the rider on a simulation elevator freefall in an elevator car. However, it isn't just freefall at the rate of 9.8 m/s2. The car is pulled down at a faster acceleration, although I didn't think about it at the time. Now I know that it is faster because during the ride, I could feel the end of my hair rising, and I also felt myself rising above the seat, being held down only by the seat belts. That means that the downward acceleration of the elevator car had to have been higher than that of gravity to overcome the 9.8m/s2, causing the "floaty" sensation.

And yes, this is much like what our field trip to the elevator would have been like, except in a much more extreme form, thank you very much. Next time I ride this ride, I'll be sure to think about Doc's visual hand motion thing, and while I'm screaming my head off, I'll explain to everyone who's riding what's happening. :]

First Post! :D

Okayyy. Well, so far AP Physics B has been quite a challenge for me. Hopefully, I can get used to this work load and understand the concepts better. But it's really great to have amazing friends who can help explain to me things I don't understand, so that's definitely a plus. Physics is different from Biology and Chemistry. Memorizing so many equations is a little hard, oh, and also figuring out when and where to use them. Once I see the work on paper, I understand why everything is there, but I don't think I would be able to do it onmy own. I really hope that changes soon. >.< I'm excited to see what kinds of crazy and fun labs we have in the future. Though I'm not really too sure about those problem sets. XP. I really hope I can survive this year, and I really will try my best, so hopefully it's good enough. I'm looking forward to a great year in Physics! :]














Right now, this is how I feel about Physics...A little confused...Or a lot confused...And my room is a mess, which happens to be a lot like my brain at this point in time...Haha.

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