Final Post

Physics is the study of matter, force and energy. Overall, I thought the class was pretty fun, but chaotic. Which basically means fun. Some lessons were kind of hard to follow but in the end there were super easy parts which made things even out for me.

I learned that I cannot draw a straight line. I also learned how deficient I am with a calculator and how bad I am keeping up with nightly homework assignments. I also learned about hot light reflects off of things no matter what the surface. I also managed to pick up little tidbits that I go off reciting, confusing my friends who were in English and angering my friends who also took Physics.

I liked that the class and course overall was so spontaneous. One moment we could be studying and the next be banging on an Inception noise button confusing the surrounding classes. It was nice to take a summer class that actually made it feel like summer even if we were at school.

As for feed back, it was fun, but honestly I couldn't stand a single one of our quarter projects. Except for maybe quarter one. Other than that, the egg drop lab didn't seem relevant, the bottle rocket was hard to test because of conflicting variables like wind, and the song one was just parodying a song using big vocab words that are nearly impossible to rhyme with anything.

--will update with pictures for the last few posts--

Unit 10: Continued

Refraction is the changing of direction and speed of a wave due to medium. The index of refraction is found by dividing the speed of light in a vacuum by the speed of light in the medium. The larger the index of refraction is, the slower light moves through the object.

When going from a fast medium to a slow medium, the light will bend towards the normal, or the perpendicular intersect of the surface the light is entering.

Converging lenses are like goggles. They make light converge further up then it normally would. In water, the index number is higher then it would be in air so the light would have to go further before it intersects. To focus that light, people wear goggles if they want to see under water. Diverging lenses make light spread out.

--will update with pictures for the last few posts--

Unit 10(?): Colors

Growing up, we always knew that red, blue and yellow were the primary colors because, between them, you could make almost any color. In light, the principle is similar but the colors are different. The primary colors of light are red, green, and blue, yellow instead being the product of red and green. The product of green and blue was a color called cyan while the mix between red and blue was magenta. These six colors make up a wheel that starts from red and goes to magenta, blue, cyan, green, and yellow back around again. The color opposite from one of the colors on the wheel is said color's complimentary color.

Unit 9: Electromagnetic waves

We learned that light moves in a straight line and at the velocity of 3 x 10^8 m/s. That means in one second, light can go to the moon and back. It also means that, in the same amount of time, light can go around the world 7 1/2 times. We learned about the concept of transparent and opaque. Transparent material lets certain waves through while opaque blocks majority (all visible light) all together. Like how an x-ray can see through your skin and muscle but your bones show up; your skin and muscle is transparent to the x-rays even though your bones are not.

Unit 9: Sound waves

Today we played with a bunch of beakers and tuning forks. We learned the idea of resonance which is an increase in amplitude of a wave by vibration caused by a force at the same frequency.  To go along with this idea, Mr. Blake showed us a video of the Takoma bridge from forty or fifty years ago. Along with resonance we learned about both reflection, or an amount of light, heat, or sound that is thrown back in such a way, and refraction, the bending of light, when light moves from one medium into another; change in the direction of waves as they pass from one medium to another; bending of the path of waves accompanied by a change in speed in wavelength of the waves.

Unit 9: Waves

Unit 9 was about waves. To find the velocity of a wave you need to multiply the wavelength by the frequency of the wave. The period of a wave = 1/frequency. We learned about what the parts of a wave were called: crest, (the top half of a wave), trough (the bottom half) and the nodes (the equilibrium point between waves). Amplitudes are the distance from the very top/bottom part of the crest/trough to the closest point on the equilibrium line thing.
Because the idea behind waves is usually energy opposed to a solid object, waves either add to each other or subtract each other for the split second that they pass depending on which way it was moving and how big it was before the collision before passing on.

I hate my laptop

Today, we tried to launch our rocket. Without altering anything, we went outside to get a feel as to how we should fix our rocket. But even though yesterday our rocket was able to stay in the air for five seconds, this one wouldn't. We ended up adding four more cardboard fins to the very top of the rocket and elongating it with the plastic of an extra bottle we had. Instead of using the grocery bag parachute we tried using the day before, we switched it for a garbage bag and tied it down with extra strings.



In the end, our rocket didn't manage to stay up in the air. Our longest time was 5.3 seconds. I think its because our rocket wasn't long enough and as a result couldn't get high enough in the air to reach the minimum required for our parachute to come out consistently.

I really don't think I learned anything from this lab except for that I like it a lot less then the egg lab. It caused a lot more stress and in the end results were really varried even when we kept things the same

Bottle Rockets Day 1

My partner and I started creating our bottle rocket. Our first trial had three wings, around the same size and position but not quite, and taped together at the top to try and trap air when it fell down. We went on the hope that the rocket would fall back down and the air that could be caught in the wings as a make shift parachute (at that time we didn't have a cone or a chute to work with). It didn't end up working. At all.

Our next design had four identical wings (taped in duct tape in case it rained) and had a rock taped to the top to balance the rocket out. We added a cone to the top (courtesy of Jasmine and her cone selling business) and folded up a plastic bag parachute inside of it. We also added another cup or so of water. The launch worked out well, just making five seconds.

--will add video later--

Power

Today we added onto our what we knew about work and learned about power.  Power is how much work you can do in how much time. In class we weighed two people and had them run up a flight of stairs while others timed them. A person with a high speed would have a large amount of power, or watts.


During class, Kimi and I were the ones to run. Because I was heavier then Kimi, it took me a little longer to run up the seventeen steps. But because our mass was different and our times relatively similar, I generated a higher power.

Unit 8: Work

In unit 8, we learned about work. Work is defined as the change in energy and can be found by multiplying net force and displacement. The unit for work is joules, or kgm/s. We learned how to calculate for gravitational potential energy (energy an object could have due to its position in a gravitational field) and kinetic energy (energy an object has while moving.) We also learned about spring potential energy. To be able to find spring potential energy, you must know the spring constant, or k.

When graphing on a force vs distance graph, the slope is k and the area under the curve is work done.

Unit 7: Momentum

The definition of momentum is the property of a moving body. Momentum is a vector quantity that can be found using the equation momentum (p)=mass x velocity. We also learned that, in an isolated system, momentum in has to equal momentum out

Impulse is the average force multiplied by the time of contact/the change in momentum.

In class, we talked about how when something runs into something, the total momentum is divided between the two. When it collides with a stationary object, a moving object will come to a halt and the stationary object, in theory would move at the same velocity the other did.

Eggdrop Lab

The idea behind our egg drop container was to have something that was small to reduce bouncing around inside the container, padded to hopefully prevent cracking from the impact when it landed, and light so it would reach maximum velocity relatively quickly. In our small air tight tupper ware container, we packed as much stuffing as would fit in order to cushion the egg. After sealing it tight, we taped spongey pieces of foam around the tupper ware to break the fall and extend the contact time.

The forces that were acting on the container were weight force down, normal force up when it lands, air resistance up.

Our egg was completely shattered. The problem probably was that since the container itself was too small and light, too much force was applied where there wasn't enough area that could take the force. Perhaps the container wasn't packed tightly enough and the egg rattled against the side. If we were to do the lab again, I'd probably layer containers to take more force before it reaches the egg container and create a cone as something to take majority of the force on the bottom. 

Happy Semester Fun Time

So... we did a lot this past semester. We studied the differences between accuracy and precision in unit one, in unit two we tried to find a way to answer the question "are you moving?" We studied motion motion as it moved in more than one dimension and learned how to measure said motion using vectors in unit three. And, in unit four, we revisited every thing we knew back in unit two and screwing with it until I could barely recognize it. (Math never was my strong suit.) In unit five, we studied Newton's Laws and I found out on my own that playing the "a motion that is in rest stays in rest" card does not put me in good standings with my mom and makes me even less likely to get out of chores.

Unit 5: Equillibrium

So... basically we did the same thing we did the day before, but on a more confusing level. We applied the three laws that we had learned the day before and, using the four newly learned forces, solved problems and shit.

Can you tell I didn't really understand?

Anyway, the four forces we talked about were weight (the force that pulls you straight down), normal (the force that makes sure you don't fall down into the center of the earth or something like that), tension (... something about being pulled by strings...), and friction (the thing that gives you a rug burn when you slide on carpets or skin your knee on a sidewalk when your friend doesn't realize you have terrible balance and thinks it would be fun to play life-saver.)

We drew free-body diagrams too... I know they're important, but at the moment, my head is killing me and I can't really describe it...

Unit 5: Newton's Laws

For the first day of unit 5, we talked about someone named Newton and some stuff he said a long time ago. We learned about three different laws in particular.

Newton's 1st Law- An object that is in motion/rest will stay in motion/rest unless acted upon by an unbalanced force.

(I tried telling my mom I couldn't help her with the dishes because it went against Newton's laws but she just took my laptop away.)
Newton's 2nd Law- Force = mass x acceleration

(Mass and acceleration are inversely related to each other. I got that wrong on the remote quiz-things. A lot.)

Newton's 3rd Law- Between two interacting objects, there are equal and opposite forces between them.

(Like when you push one of your annoying friends in front of a bus. They hit the bus just as hard as the bus hits them, though one gets off with only a messed up paint job and the other is broken. Which is which, you decide.)

^Newton       

Unit 4: 2D Kinematics (continued)

For this part of the unit, we launched rockets.

Using the equation d=1/2at^2 +Vot, we attempted to calculate the distance our rocket would go in order hit our teacher with rockets. We were given three different caps, labeled low, medium and high respectively, and were let free to do basically whatever we wanted. Following the sole rule of not injuring anyone.

Rules ruin all the fun.

Anyways, after calculating the velocity of each of the caps, we decided to go with the medium cap because it had the most reliable results.

Sadly, we missed every time. (I'm just kidding. Oh my god please don't fail me.)

 If you don't understand, we can't be friends.

Unit 4: 2D Kinematics

Ok, so if I were to be totally honest, I didn't understand this unit at all. But here's the way I kind of see it.

2D kinematics is almost identical to regular kinematics, except for that it's possible to go in more than one direction. Like if you throw a ball up to your right. It doesn't go straight up and come back down, nor does it travel to your right in a horizontal line, never slowing down (unless it runs into an unbalanced opposing force!! I remember that part!). No. It flies up in the air, moving to the right.

The way to measure this is fairly simple; you just need to remember the "Vegas rule." Ever heard of the term "what happens in Vegas stays in Vegas?" What happens on the x-axis stays on the x-axis and vice-versa.

We also covered something about SOHCAHTOA, which I completely forgot about as soon as I finished my Geom final exam last year (that's untrue... I forgot it before I started it), but for the life of me I can't remember...

This is why I didn't ask to take math over the summer.

This past quarter... (... oops)

We learned about many things this first quarter in physics.

We studied were scientific notation, the metric system and dimensional analysis. Scientific notation is an easier way to represent extremely large or extremely small numbers in terms of decimal numbers between 1 and 10 multiplied by a power of ten. 0.0000000348 can also be written as 3.48 x 10^-8.

We also studied the differences between scalar and vector quantities. Scalar is a quantity that has magnitude while a vector is a value that has both magnitude and direction (oh yeah!). An example of this would be, if a scalar quantity is 10 steps, a vector quantity would be 10 steps north. Scalar is measured in distance (meters) and vector is measured in displacement (also in meters). Distance in physics can simply be defined as how far. Displacement is defined as distance with direction.

Unit 3: Acceleration (continued)

In unit 3, we focused on acceleration and the variables that also affect it like velocity, time and distance. According to a theory of Galileo's, discovered that freely falling bodies, heavy or light, have the same, constant acceleration and that this acceleration is due to gravity. We spent today trying to discover that on our own through our own experiments.

An example we were shown in class was that if a tennis ball and a volleyball were dropped at the same height at the same time (in an air-less environment), even though the mass of each ball was different, they would land at the same time. This is because the pull of gravity is always constant. Heavier things don't fall faster then lighter things (in an air-less environment, as air resistance is the reason paper is an exception on Earth)

---will post picture tomorrow--

Unit 3: Acceleration

In unit 3, our aim was to study motion motion as it moves in more than one dimension and learn how to measure said motion using vectors. To start our studies, we went outside with a skateboard (or whatever we called it... the danger board?) and set in on top of a hill. We measured the time it took for the person on the board to pass each of the timers that were spread out over 50 meters at 5 meter intervals. Because acceleration happens, the more time that went on, the more distance the boarder covered.

A picture of the graph with the data from the experiment because I'm lame and never bring my phone with me when we do things I can take real pictures of for this.

Unit 2 (Continued): Moa Kinematics

During the second part of unit 2, we expanded on the idea of kinematics. We analyzed graphs and tried to replicate them using a motion sensor. We found out the differences between a velocity vs time graph and a distance vs time graph and how to read and pick out the information we needed to know from a vt graph, like distance and slope, even though the way it looked and the way we found it were so different. Instead of drawing a diagonal line to represent slope like we did before, a straight line is drawn at the slope number itself (if it is constant) and moves either down or up accordingly if changed.

http://www.physicsclassroom.com/class/1dkin/U1L4a2.gif

Unit 2: Kinematics

During unit 2 of physics, we studied kinematics, or the study of motion. The question we were asked at the start of the unit was "are you moving?" The only way to answer the question was with another one: "relative to what?" All motion is relative. A car could be traveling 30 mph in one direction (relative to the ground) and another car could be traveling the same speed in the opposite direction, but relative to each other it appears to one as if the other is traveling at 60 mph while they stayed still.

It's all a matter of perspective.

We learned the between scalar and vector quantities. Scalar is a quantity that has magnitude while a vector is a value that has both magnitude and direction (oh yeah!). An example of this would be, if a scalar quantity is 10 steps, a vector quantity would be 10 steps north. Scalar is measured in distance (meters) and vector is measured in displacement (also in meters). Distance in physics can simply be defined as how far. Displacement is defined as distance with direction.

The lab we did in class was called the Physics Olympics. Timed, people would run, hop, and balance binders across a span of 50 meters. Since I hid at the 50 meter line and didn't actually participate in anything, here's a picture of a stopwatch because it's relevant.

http://preprofessionalmusings.files.wordpress.com/2010/08/ist2_6685580-stop-watch.jpg

Unit 1: Intro to Physics

During unit 1 of physics, we studied the differences between accuracy and precision. Accuracy is how close the measurements are relative to the real value while precision is how close the measurements are relative to each other. In other words, accuracy measures exactness/correctness and precision is based on if the results can be replicated.

Other things we studied were scientific notation, the metric system and dimensional analysis. Scientific notation is an easier way to represent extremely large or extremely small numbers in terms of decimal numbers between 1 and 10 multiplied by a power of ten. 0.0000000348 can also be written as 3.48 x 10^-8.

The lab we did in class revolved around pendulums. Through that, I learned that both mass and angle of release (of the pendulum) had nothing to do with period length contrary to what I previously thought.

The picture I chose to use was one that Mr. Blake took during the lab of my lab group. I decided to use this because it was easily accessible (thank you class website) and since there's no real chance of getting sued for using this picture on my blog I don't really have to go out and site the source (though I kind of already did).

Nobody Read This Post So I Could Edit It If I Wanted To

My name is Breana. I am 15 years old and live in Mililani, Hawaii. I have been attending Punahou since 6th grade. I took the required science classes all the way up through freshman year before deciding to take Biology and Geology of Hawaii instead of Chemistry sophomore year. Last year I took Geometry but in week or so between the end of final exams and the start of summer school I've somehow forgotten virtually everything that I had learned this past year.

By completing this course, I hope to gain a science credit (i.e. not failing) so I can clear more room in my junior year schedule to take more courses that interest me that I wouldn't have been able to done with a full year of Physics.

My picture:

I chose this picture because I've seen The Avengers twice in the past month or so and I still have to work on the Dimensional Analysis worksheet and figure out the review packet so I chose a random thing off my desktop.

Plus Chris Hemsworth looks like a Disney princess with that tiara.