Reflection on Physics - the end

What is physics?

Physics is science dealing with energy and motion that relates to real life examples and occurrences. Physics is everywhere in our world, from the sky to the ground, and how to get there in between. Physics is the explanation for nature, and how our universe works.

What did you learn from this class?

From this class, I gained so much knowledge. As there were times when I wanted to break my pencil in half and run around the quad, there were equally, if not more moments where I was laughing nonstop. This class was so compressed, I was worried that I would get behind and perform poorly. However, with help from my friends, I got help when I needed it. Mr. Blake would always patiently listen to my questions, and help me figure out what I didn't understand. Unfathomable concepts became basics to my physics brain. Before the course, I didn't expect anything close to the summer I've had.

What did you like about the class?
I absolutely loved how each concept was relative to something in our daily lives. Doing our homework was pretty easy, because we could identify the concepts from class. Mr. Blake gave us such clear examples and made sure we understood each idea before we left for home.

What could be modified to improve on the class?
I think some labs could've been modified or replaced by a lab more related to the unit idea.

Commentary/Feedback?
I had a lot of fun and learned so much, thank you Mr. Blake!!

not as it appears - unit 10

Refraction is the changing of wave speeds due to changes in mediums. Today, we did many demos and worksheet problems to learn how these certain refractions look in real life. The index of refraction is represented with the letter n. n = c/v, which is the speed of light in a vacuum (3 x 10 ^8 m/s), divided by the speed of light in the medium. Some indexes of refractions we learned, are air (1), water (1.33), glass (1.5) and diamonds (2.42). If we put this in the c/v = n equation, you can get each speed of light in the medium.
Refraction is dependent on the medium, where if there is change in 2 media, bending will occur. Snell's law is an equation that can be applied to refraction. With this equation, we can find the angle or the index of refraction. The critical angle happens when there is change in media. All critical angles are relative to the normal.

when will my reflection show? - unit 10

Today, we did a lot about mirrors, colors, shadows and reflection. There are two types of reflections: specular and diffuse. A specular reflection is a smooth surface relative to its' wavelength. A diffuse reflection is a bumpy surface relative to its' wavelength. Most objects are diffuse, and because of it's not smooth surface, it allows us to see the image. As I said in the last blog post, a mirror is opaque, and gives off a specular reflection of light. In this picture, I can see my full body in the mirror, because the mirror is greater then half the length of my body. My feet to my head reflect in the mirror, which reflects back to my eye, which is how I see my whole body. If I were skipping towards myself in the mirror at 3 m/s, the image of me in the mirror and my real body would approach each other at 6 m/s. Because I am using a flat mirror, there is no center of curvature so light isn't conveyed. Because the light isn't conveyed, I can see my reflection very clearly and well.

what you see - unit 10

Today we learned that when you are looking at an object, you aren't actually seeing the object. Instead, light is reflected off of the object, which is what you see. Electromagnetic waves (EM), or electromagnetic radiation, is radiation consisting of self-sustaining oscillating electric and magnetic fields at 90˚ angles facing each other and at the direction of the motion of the em wave is transmitted through a medium such as air or water. It does not require a supporting medium and travels through empty space at the speed of light.

We also learned that objects are either transparent or opaque. If they are transparent, the em frequency is allowed to go through it. If opaque, the em frequency is NOT allowed to go through. The little trinket I bought in china town many years ago on a field trip, is an example of a transparent object. I know that it is transparent because light can go through it, and I can see from one side to another if I look through the glass. Some objects that are not transparent, are mirrors, books, carpet etc.

unit 9

 

Continuing with the topic of waves, today we learned about sound waves. A few key ideas we learned, were that object want to vibrate, and that noise is a sound that is incoherent. Also, sounds need a medium to travel through.
Using a tuning fork, we did multiple labs showing us how sound travels. The average human can hear about 20 Hz - 20,000 Hz. Animals who can hear higher frequencies are called ultrasonic, whereas the opposite, hearing lower frequencies are called infrasonic. 

In this picture that was taken 5-6 years ago, I am with the cutest water mammal, the dolphin! Out of curiosity, I looked up the range of frequencies they can hear. I found that it was a much bigger range (to no surprise), 250 - 150,000 Hz!

Using the beautiful creature, I created a sample problem that shows how to find the frequency, given the speed and wavelength.
If a wave has a wavelength of 2.17 meters and the speed of sound in water is 923,580 m/s, what is the frequency a dolphin hears in this water?

V= ƒλ
92,580 m/s = f (2.17m)
f = 42,664 Hz, 42.7 kHz

Motion of the Ocean - Unit 9

Today we were introduced to waves and wavelengths. From chemistry, I was somewhat familiar with what waves were, and how they contributed to our world. However, there were a lot more aspects and details that we didn't learn, that make "waves" a topic a little more difficult to understand.

I found that when Mr. Blake talked about the ocean's waves in terms of the physics waves, I understood the whole concept a lot better. Below, I will define words that are affiliated with waves, but in terms of the ocean water.

Frequency: The number of waves it takes per one second.
Hertz: Units of frequency (if 3 small waves came in one second that would be 3 Hz. # of cycles/secs)
Amplitude: The height of a wave measuring from sea level.
Wave speed: How fast the wave comes
Wavelength: How long the wave is.



Interference is when two waves meet in the ocean. There are two types of interference: Constructive and destructive. Constructive is when two waves coming from opposite directions meet and create a very large wave, whereas destructive is when two waves coming from above and below meet, creating a completely flat sea level when the leave.

The girl in the picture below is cruising in the water with her doughnut floaty. If 2 waves pass her in three seconds, the speed of the wave can be measured as followed:

V= ƒλ
V = 3/2 Hz(2.5 m)
V=1.5(2.5)
V= 3.75 m/s

What is it's period, or the time it takes for one complete cycle to occur?
T=1/f
T = 1/1.5
T = 2/3, 0.67 sec

Bottle Rocket analysis - quarter 3

What design features worked?
           The size of the fins and how we wrapped duct tape around them seemed to work fine. A few time the rocket landed on a fin and it came off, because the fins were only attached to the bottle by hot glue, but after we duct taped the glued fins to the bottle the fins never came off. The bottle itself never broke apart. Our first nose cone was very good because of the thick paper we used. However, it got stuck in the tree and we were unable to retreive it. We didn't have any more of that paper so we had to use a thinner construction paper. We wrapped the cone in the duct tape too, but it was still flismy, and crushed easily. The only design that didn't work was the parachute. For some reason, we couldn't get it to come out of the cone. Although we tried folding it and placing it inside the cone various different ways, it was never effective.

Launch condition - amount of H2o PSI?
         When we launched it twice in the morning (8ish), there was no wind. We used a lot of water (about 1 L) and realized that it had too much water and it was weighing it down, which constrained it from reaching a higher height. We then tried a little less water (about 3 party cups full of water) and it worked a lot better. We tried to get as much PSI or pound/square inch as we could. We ended up with about 100 or 120 PSI, the highest PSI we could get.

What this taught you about physics and otherwise.
           I learned that there are always variable you don't know about, or don't realize that exist. It's very hard to manipulate your experiment when you are outside. I also learned that expirements are very hard to reproduce, and very hard to predict the outcome - the outcome is different every time!
           Otherwise, I learned that maybe there is such thing as fate, and whatever that's meant to be will happen! I also realized how frustrating it is when something doesn't go the way you planned it and you know why but can't make it change (like with the parachute). Lastly, NEVER GIVE UP! You never know what might happen!

Our highest time in the air: 9.1 sec. Overall, I am very proud of our rocket. We got the second highest time in the class.