THIS IS IT - A Review and Reflection of my Summer Physics Experience

Wow, I must say that even though I knew it would only last less than one summer - I can't believe summer school physics is over! It's truly bittersweet! Looking back I know that I learned a lot and with the help of Mr. Blake and my classmates I've placed myself in a better position for success in the upcoming year (or at least a more relaxed schedule).

I appreciate all the knowledge I've gained over the last few weeks! All of it is so valuable and some of it genuinely surprised me in how challenging it was and how relevant it is to my life and the world around me. Namely, when we learned about frequency and sound, I got so excited because music is my lifelong passion. I learned the science behind how harmonies are formed! When they have complimentary frequencies whose waves match up or coincide, the sound is beautiful! Also, we learned that sound travels at the same speed, regardless of frequency, in the same medium. So no matter the pitch, the sound will reach your ear in the same amount of time in the same medium! Lastly, sound waves can't be transmitted without a medium (unlike electromagnetic waves) - which basically means that my dream of being a guitar playing astronaut who serenades aliens with my smooth jazz is out the window.

Another big thing I enjoyed learning was some of the more, what could considered, basic concepts of kinematics only because that isn't something that you just read about on some worksheets, its something that you see everyday! For example, force = mass X acceleration! Things with more mass have have more force which is why if a bike came speeding towards you it would be less scary than if a buss with more force did! Similarly, momentum = mass X velocity! Things with more mass will have more momentum! This always made me think of football and gymnastics! The more lean wide receivers are easier to stop than the huge linebackers because they have less mass and therefore less momentum! With gymnastics, things like vault and double-mini are all about momentum, you run faster so you can increase your velocity so you'll have more momentum to release in a slue of glorious flips and tricks.

In conclusion this class was great! Everyone was so laid back and helpful that it really made learning an enjoyable experience. I'm so grateful for the valuable knowledge and awesome memories that I'm taking away from this summer!

Unit 10 Post - 7/20: Light Refraction!

Did you know that light travels at different speeds in different mediums? This causes light to bend which manipulates how you see things in glass or water opposed to in air. The fastest light can possibly travel is 3X10^8 m/s. A new value, the index of refraction ("n") is a ratio for how fast light travels in a specific medium. The lower the "n" value, the faster it travels in that medium. The n for air is 1, for water is 1.3, for glass is 1.5, and for diamond is 2.42. This explains why objects are distorted when looked at through water or glass! The formula used to find this is called "Shell's Law": n(1)(sine of theta1) =  n(2)(sine of theta2). The light bends and makes the position and orientation appear differently! If light is traveling from a fast medium to a slow one, it will bend towards "normal" (perpendicular to the surface) from the path it was originally on. But if it's traveling from a slow medium, like glass, to a faster one, like air, it will bend away from the "normal" of the surface. Light can also get trapped! The n of the first medium is greater than the n of the second (a slow to fast medium), light can't escape that medium and will reflect within it as a result. The angle at which this will start to happen is called the critical angle. You calculate this using the formula: sin-1(n2/n1)!

Unit 10 Post - 7/19: Mirror Mirror on the Wall

Lights, mirrors, and reflections are truly some of the most complicated physics concepts we've yet to explore. Basically there are two different situations you can deal with, the Law of Reflections. If light hits a flat mirror, it reflects off of that mirror at the same angle it hit the mirror. The image will also be upright and not distorted. If light hits a concave mirror, the image will be distorted in both size and orientation and the beam of light doesn't come back at the same angle it contacted the mirror.

In this picture, I'm shining the light into a mirror, the light bounces off of it directly and at the same angle that it hit the mirror, and reflects onto my face! 

The other thing we learned today was about colors! Colors in physics are very different than colors in pigments. In physics the primary colors are blue, green, and red. All of them together make white and none of them make black. Green + red = yellow, green + blue = cyan, and blue + red = magenta. Complimentary colors are two colors that combine to make white, like yellow and blue. In class, it was so much fun playing with the lasers and the sheets of colored light because it make these confusing concepts really come to life!

Unit 10 Post - 7/18: LIGHTS, LIGHTS LIGHTS!

Look up, look down, look all around... that's physics baby? Something as simple as seeing can be understood properly through physics. You don't see light, rather, light allows you to see. When light bounces off of a particular object and reflects onto your eyes - you see it! When the lights go out, when its dark outside, you can't see because your eyes aren't receiving any rebounded light. It may seem overly simple and mondane, but its good to understand. The speed at which light travels to your eyes is 3X10^8 m/s^2. Beat that Hussein Bolt... beat that.

Additionally, light travels through objects that are either transparent or opaque. In a transparent object, electromagnetic frequencies of light are able to go through - as seen in my fishtank below! However, in opaque objects these waves cannot. Its simple to think of this easily as things you can see through and things you cannot.

Unit 9 Post - 7/15: Consequence of SOUND!

Sound is a longitudinal wave (meaning it moves parallel to the wave motion) that cannot be transmitted without a medium - which is why there's no sound in outer space. It's also a non-dispersive wave meaning all the waves travel at the same speed in the same medium regardless of frequency, so when you listen to music all the pitches reach your ear at the same time allowing tempo and rhythm to stay intact. At sea level this speed of sound is 340. 29 which is slower than the speed of light - meaning you will see motion happen before you hear it!

The human hearing range is from 20 Hz to about 20,000 Hz, and as you age this range decreases. Society manipulates that by instituting whistles and horns that can only be heard by younger people in order to keep them away from certain place as is in England.

When you listen to your ipod, the sound is traveling through the metal in the earphone and the air between it and your ear. This is a very short distance, thus if you listened to the same song at a stationary volume on your ipod and then through a speaker, it would sound louder on your ipod.

Unit 9 Post - 7/14: That's the WAVE!

From the cooperation of everyone in a large stadium, to the crashing beaches of our island, to the passionate twangs of music - waves are everywhere. Even in physics! Waves are a disturbance in energy caused by vibration that acts in a medium, the most effective one being a solid because the molecules are closer together and can transfer said energy more efficiently.

The different parts of a wave are the crest, trophs, and amplitudes. The help us measure the waves length and speed. A wave that's moving slowly has a low frequency and a long wavelength, while a wave that is moving quickly has a high frequency and a short wavelength.

Waves can interact with each other too! Unlike the normal physics of mass, waves can occupy the same space at the same time because of a property called superposition! Then two waves combine with each other, to briefly create a wave that is the sum of the two initial waves, its called constructive interference. When two waves of equal magnitude that are moving in the oposite direction and are oposite values (one positive one negative) interact, they cancel each others energies out for a moment resulting in a flat line - this is called deconstructive interference.

A special wave, called a standing wave, is created when two waves of equal wave speed and magnitude are moving in the opposite direction and interact. This video is a demonstration of that in which our shoulders are the nodes - parts of the standing wave that are stationary, and our hands are the anti-nodes - parts of the standing wave that are moving.

7/13: ROCKET LAUNCH FINAL DAY

Today was the official day of our rocket launches! Sam and I had planned on using balloons to keep our rocket in the air. We played around with this idea a lot and approached in with various methods... but in the end, it was gravity who took the victory.

I think that all in all we had the right concept, we just didn't execute them in the right combination! When it comes to what features were involved, the first thing we tried was using 4 regular balloons filled with oxygen. We taped them on strings relatively close to the bottle so the balloons and the bottle would be close to each other. We were hoping this would provide a huge amount of drag and act as a glorified parachute of sorts... and it did! ... Just not quite in the way we'd hoped. We figured that if we pumped it up so there was a lot of H20 PSI (we put in about 70) then we would minimize the effect of the balloons drag on the way up and the amount of drag it produced on the way down would give us a good time. However, we only taped the balloons to the bottle with small amounts of scotch tape... so when all the pressure blasted the rocket upwards, the tape couldn't handle it and the balloons were left behind.

Back to the drawing board! We then decided to try and sticking a deflated balloon into the top of the nozzle  opposite from where the water goes. We didn't really know why we were doing this, we just did it. We pumped a high amount of PSI - again around 70 - and noticed that this feature also worked pretty well. It didn't affect how fast and high the balloon shot into the air which was good because at 70 PSI it went pretty high/fast. However it did slow the fall of the bottle. We kept that idea in the back of our mind while we headed back to modify our rocket for the last time... our final ultimatum.

We had a helium tank and nearly 70 balloons. We did our research and found that 1 L of helium will lift 1 gram of mass. Each balloon could hold about 15 L of helium and our rocket was a little less than 20 grams. It was fool proof, or so we thought. So we filled 16 balloons with helium, leaving our tank virtually empty, and put strings on them and used hot glue and numerous rounds of duct tape to attach them to the bottle, we learned from our mistake of not securing the balloons the first time. We also removed two of the four fins from the rocket in order to make it lighter so the balloons could carry it. With no water in the bottle, the balloons allowed the rocket to float for about 2 seconds before falling at an extremely slow rate, so we felt very confident about our idea. We decided it would be best to not pump too much PSI into the bottle because we didn't want the balloons to come off and figured they could do all the heavy lifting on their own (since all the water from the bottle comes out as soon as its launched, and the balloons could support the empty bottle). We only put about 1/16 water in our bottle because we didn't want to take any chances of anything weighting the balloons down. This is where we went wrong... we only pumped 25 PSI into the bottle, so when we launched it it didn't go very high at all; and although it hovered for a moment before falling very very slowly - it just didn't have a high enough initial height to make enough of a difference and our final time was 4.9 seconds. OH WELLLL : (

For a physics project, I had quite a difficult time trying to understand how what we learned applied to this. I mean we didn't necessarily have any formulas we could've used to find how to make the rocket stay in the air or anything. However this taught me a lot about drag and pressure. Drag may be a good thing when it slows a falling object, but the reality that it slows an object that's accelerating upwards as well! It's sort of a double edged sword, and with something like balloons, you will have a very high amount of drag. When it comes to pressure, I think the main thing I took away from this project is that the more pressure you have the better! Don't try to manipulate your pressure to do what you think is right, rather just get as much pressure you can into your rocket, and then adjust your rocket accordingly. Make your rocket adjust to the pressure, don't adjust the pressure to your rocket... and TURN THAT SUCKER UP! The reality is, the more pressure you have, the higher your rocket will go and the longer time you'll have. I'm sure there are negligible acceptions to this but for the most part, pump away! Our second balloon launch - with the helium balloons - was extremely secured to the balloon, so had we pumped a high amount of pressure into the rocket, it would've had more air time up and therefore more time to come down (very very very slowly). As far as otherwise, apparently this project taught me that... no matter what we're all doomed to fail so too bad? NAHHH This project was a great lesson in patience and happiness. It was weird seeing how people were so emotionally attatched to this project! I mean after tthe launches (mostly failures) people were all depressed and gloomy! Why?! Chin-up, life goes on, the sun will still rise tomorrow and you'll be just as young and good looking. Taking things too seriously can be dangerous, so choose happiness... it's so much easier : ) In conclusion this was a really fun project, I kinda wish we'd had an extra day to play around with ideas just because it's fun to experiment but all in all it was pretty darn cool!

7/12 ROCKET POWER!

Our assignment is to build a water bottle rocket that will stay in the air for at least 10 seconds when launched using a water-pressure system. Sam and I got to work with this challenging assignment

First we took our two 2L bottles and lengthened our entire rocket by cutting out bottom of the second and fastening it to the bottom of the outer one. Now we had two caps and the rocket is longer and more stable!

 

Next, it was time to add fins to our rocket. We measured how large we wanted them based on the fact that we didn't want them to big too big and weigh down the rocket, but we needed them to be large enough to provide stability and possibly some air resistance. We used cardboard because its thick and convenient and wrapped it in water proof duct-tape. Then we secured it to the base of the the rocket using more duct-tape and a hot glue gun.

 

Now it was parachute time! We took a thin plastic bag and shortened a little bit. then we poked four holes near its base and strung holes through it. Then we connected all those strings to a base of tape and hot glue. From that base we took two strings that we taped directly to the bottle, then we tucked the entire parachute into the top hole of the rocket.

It was launch time! The goal was 5 seconds, and unfortunately things didn't go out way... at all. On our first trial we got around 3.5 seconds. We were a little bit surprised but figured it was just an unlucky launch that could be easily improved with simple tweaks. On our second try the rocket didn't even shoot straight up and we only had a 1.7 flight time. On both trials our parachute didn't deploy at all. We've definitely our work cut out for us if we're going to make 10 seconds tomorrow... oh do we? ha ha ha... Ha Ha Ha... MUAHAHAHAHAHAHA!!! *evil laugh* *lightning strike*

Unit 8 Post - 7/11: Power!

Work is basically "what" you're doing, which is why its defined by force (ma) times distance!
Power takes that one step further, its "how" you do what your doing, the rate at which you work. Whether you work faster or slower defines your power. You simply divide total work energy by time to find the rate   at which work is done - POWER - which is measured in Watts!

Power doesn't necessarily determine how much work you do, just how fast you do it! Work isn't a property of an object, but power is! Work is simply the noun while power is the adjective, thinking about it that way is so much more helpful!

Unit 8 Post - 7/08: Work and Energy

Today we learned about work and energy. I always thought work meant putting effort into something; for example we had someone holding heavy boxes and I thought that was work because of the fact that it required effort and energy to do! It's not like he could've just held those boxes for the rest of his life! But in physics sense, work is a change in energy: Work = Force X Distance (joules)
Work only happens when you're working against a force, so if its a frictionless environment then work is impossible. But if your working against gravity or some form of friction then your have to put in WORK!

Energy isn't created or lost, it simply changes form - this is the law of conservation of energy. The two main forms of energy we're exploring are kinetic energy (motion) and potential energy
Potential Energy is calculated by weight X height. You can think of it as the amount of energy "stored" in the object with the potential to release. When that energy is released, it changes into kinetic energy!
Kinetic energy is basically the energy of motion! The total energy of your system stays the same so as kinetic energy decreases, potential energy increases and vise-versa. They have an inverse relationship.

In this picture, the fact that I'm standing at an altitude that is higher than my equilibrium (the ground) means I have potential energy.
PE = mgh (potential energy = mass X acceleration of gravity X height)
PE = 55.79 kg X 9.8 m/s^2 X 0.64 meters
My potential energy = 349.91 Joules

In this picture I am falling with kinetic energy. I simply stepped off the bench to release my potential energy and change it to energy of motion.
KE = 1/2MV^2 (kinetic energy = half of the mass X velocity squared)
KE = 1/2(55.79 kg)(assumed velocity of 0.5 m/x)^2
My kinetic energy = 6.97 Joules

Unit 7 Post - 7/07: EGG DROP (it like it's hot)

Today we conducted an experiment in which we were split into groups and given an egg. With that egg we had to build a contraption, not to exceed 35 cm in every dimension, in which to place the egg so that it could survive an approximate 10 meter drop.

My group built this: The Fluffy Fail

The brown paper bag on the top contains the egg in an individual zip-lock bag, surrounded by a bed of cotton balls in plastic bag, surrounded by a bed of marshmallows in a plastic bag, resting on a bed of plastic soda can rings - all wrapped in said brown paper bag. The brown paper bag is on a pillow that has been cut open by slitting in order to keep it from bouncing. The pillow sits on a mesh of plastic bags... we aren't sure if that really had a defined purpose but figured it couldn't hurt.

Just so you have an idea: Nude Egg Drop

We were dropping the eggs from more than a significant height under nothing but the good ol' force of gravity.

We conducted a practice run long before the drop with a practice egg I brought from home, it was successful! We didn't drop it from quite as high as the real one, but none the less were very excited knowing we were more than on the right track. We made some modifications afterwards to create the finished product you saw we tested. We cut the pillow - which looking back I think was destructive and unnecessary, we removed two red sponges that were between the bag and the pillow, which I also think was a bad idea, and we added the bed of plastic bags under the pillow - also regretted. I guess because our practice run went so well, we didn't think to just let it be - we thought anything we did to it could only make it better! 

The plan was to rely solely on cushion and padding. We weren't trying to manipulate acceleration, gravity, or the fall, were were just hoping we had put enough padding that it wouldn't matter. 

In conclusion, all the complicated things we added to the top in the brown bag (most of them unnecessary) caused the top part of our contraption - where the egg was - to be heavier than the bottom. So when we dropped it, the contraption flipped and fell directly on the egg. Game over.  In my honest opinion, if the contraption had landed right-side up, it would've worked. Our pillow was extremely thick and cushioned, and because it was slit open it couldn't possibly bounce. 

If i had to do it again, I wouldn't have put the plastic soda can rings in the brown bag, I would have cut the pillow a lot less than we did (but still had a small amount of slits just to let the air release so it wouldn't bounce), kept the red sponges between the pillow and brown bag, and... well I guess I would've prayed before we dropped it. This worked during the practice run - so I guess I learned not to "fix" it if it isn't broken

Unit 7 Post - 7/06: Impulse and More Momentum

Impulse is the change in momentum of an object; it's the average force upon the object at any given time (multiplied by the time). You calculate impulse by subtracting the object's final momentum (m*v) from its original momentum (m*vo). Finding the impulse is important because it helps you understand the relative times and and velocities for the motion you're exploring.

With regards to the science of physics, there are two types of collisions - elastic and inelastic. An elastic collision is one where all momentum and kinetic energy (motion energy) are conserved. The value that it begins with is the same as the value it ends with. In an inelastic collision, the objects stick together and become one. They then share an equal velocity based off the transfer of the original velocity in relation to their difference (if any) in mass.

Unit 7 Post - 7/05: Conservation of Momentum

In systems involving force, velocities, and momenta; the basic concept to be understood is that velocities can be changed (usually transferred) but momentum is the same. Mass plays a significant role in this because momentum is the vector product of mass and velocity - so the greater the mass the greater the momentum. Velocity is generally transferred from one object to another when they come in contact with each other and equal masses; but if they don't they transfer velocities in proportion to the differences of their masses.  But all in all, momentum is conserved, the amount that is put into the system is the amount that will come out as well - regardless of a change in mass or velocity.

 

http://webpages.uah.edu/~wilderd/resources.html

This picture demonstrates the simple concept. The two balls have the same mass so their velocities will be transferred equally. So when the white ball hits the yellow ball, the yellow ball will move with the same force that it was hit - while the white ball will sit still because that's the velocity it was hit at (when you hit something... that something hits you just as hard). The momentum of the entire reaction stays the same even though the velocities are transferred. 

http://www.russbrown.com/motorcycle-lawyer-blog/dls/car-hits-bike-300x196.jpg

This tragic picture is a real-life application of this concept. The car and the bicycle hit each other with the same amount of force and the amount of momentum in the collision remains constant. However, mass of the motorcycle is much less than that of the car, thus the motorcycle felt much more of the force while the car did not (more mass = more inertia = requires more force to accelerate), leaving the motorcycle in ruins.

PHYSICS REVIEW AND REFLECTION - SEMESTER 1

In my first semester of physics this summer I have been challenged, frustrated, and on the verge of giving up. I've been inspired, enlightened, impressed, and surprised. I'm so happy to be in this class - not just because it means no science for the entire school year, but because I'm learning so much about the science of the world around me while having fun!

When it comes to discussing what I learned, it would be so easy to go on and on about the equations, formulas, scientific concepts, laws, and technicalities covered on paper. But if that's what you're interested in, just read my earlier posts! Learning is so much more than that! This class has taught me discipline and avoiding procrastination. Because we always have to post on our blogs every night by a certain time, and with my busy schedule, there's no room to slack or put things off. I'm able to stay focused and on top of what I need to do. Secondly, this class has taught me persistance and critical thinking. When physics gets hard, as it constantly does, it would be easy to give up and mutter around hoping someone will step in and save the day. However, that doesn't happen here or in the real world. When I'm confused and frustrated I've learned to push through that wall and challenge myself! Lastly, physics has taught me how to be a better team player and work with others more. I've always hated group projects and the like because in my mind it's easier to worry about yourself and no one else. However, we did so many group labs that you didn't really have a choice but to learn to work with others without taking too much charge or bumming off of others' efforts.

The things I really enjoy about physics class is the remotes and how we use them to test our knowledge without too much risk. It helps you learn because even if you make a mistake it's ok, but at the same time it helps you exercise the knowledge that you do know! Another thing I like is when we have class and group discussions about the concepts that we're exploring because students helping students is very effective because you're communicating on a level that you understand and it also gives you the opportunity to do soem teaching yourself! I also enjoy those simple worksheets that you shouldn't over-think because they lay everything out that you need to know in a simple way that isn't too intimidating.

Some of the things I feel challenged with in physics was, like I said, the group work - namely the labs. It often felt like we were thrown into the ocean with no life-vest. We'd just learned a concept or idea and then are expected to execute it on our own? That doesn't work so well; instructions can sometimes be confusing and hard to follow and more often than not when the lab finally gets completed I see absolutely no relevance or significance with it!

I chose this picture because the jumping reminded me of many of the concepts we learned this semester regarding forces, acceleration, gravity, and acceleration! In this picture you can see all of those things brought to life! However, this picture is a celebration from my sister's college graduation at the start of the summer and I also chose it because it sentimentally represents my much more "mini" graduation from my first semester of physics! WHOOOHOOOO!