Newton's 3rd Law and Interaction Diagrams

Learning Goal 4.2- I can analyze motion within the framework of Newton's 3 Laws.

Prior to this week, I knew Newton's 3rd Law as "for every reaction there is an equal and opposite reaction". In class, I learned it more precisely as "all forces come in mutual interaction pairs". I also learned that the two forces in a 3rd Law pair cat on the different objects, are of the same type, and are equal and opposite. I was then able to apply this to interaction diagrams, which detail the forces acting between objects, as well as free body diagrams. 

Quiz 4.1

This past Friday, we took a quiz on learning goal 4.1. I felt pretty good about the quiz coming in, and after looking at the answer key, I think I did pretty well. I definitely liked the multiple choice format on some of the questions on the quiz, as well as the optional challenge problems. Overall, I feel pretty good about the quiz as well as my understanding of learning goal 4.1. 

Motion Mapping

Learning Goal 4.1: I can describe motion (in particular, rates of change) in a variety of quantitative and qualitative ways.

This past week we learned to make make and analyze motion maps and graphs. We tooks videos of basketball shots and used the the path of the ball going into the air and coming back down to create a parabola. We then drew several velocity vs time graphs and motion maps. I understood the difference between the two for the most part, and the main concepts seemed to make sense to me.

Unit 3 Project

For my project for Unit 3, I chose to to the advanced problem solving worksheet for learning goals 3.2 and 3.3. I haven't done much of it yet, but from what I have done the work fits the description of advanced, as it has been pretty challenging so far. I think that this problem set should be helpful in preparing for the upcoming test. 

Momentum

3.2 I can apply momentum conservation to closed systems, and can reason about momentum transfer between systems.

This week we learned about momentum through different labs involving both elastic and inelastic collisions. I learned that in an elastic collision, kinetic energy is better conserved than momentum, and in an inelastic collision, momentum is better conserved than kinetic energy. It took me a while to understand the concepts that were presented through the labs, but after comparing the outcomes in each lab it was easier to understand. One thing I'm don't fully understand is the difference between velocity and momentum. 

Spring Forces and Pulley Systems

Learning Goal 3.1 I can apply energy conservation to closed systems, and can reason about energy transfer between systems.

So far in this unit we've learned about how force, gravity, energy, and work are all related. I understand most of the equations we've learned, but applying them had been a bit difficult for me, as it's not always clear when and which equation to use. Deepening my understanding of the concepts behind these equations will probably help me fix this issue. Both the pulley systems and spring forces activity helped me understand that work is the area on a graph bounded by a force times distance diagram. In the spring activity it was interesting to see how distance stretched varied among the springs depending on the force applied.

Unit 2 Project

Learning Goal 2.2: I can reason and make quantitative predictions about real and virtual images formed by lenses and mirrors.

For my Unit 2 project, I chose to make a poster. The poster will cover the differences between real and virtual images and the difference by converging/diverging lenses and mirrors. Another thing I hope to add is predicting the magnification, orientation, and position of the images formed through mirrors and lenses.

Real and Virtual Images

Learning Goal 2.2: I can reason and make quantitative predictions about real and virtual images formed by lenses and mirrors.

This week, we talked about convex and concave mirrors, along with real and virtual images. While I didn't fully understand the difference between real and virtual images, there were still some pretty cool things that I observed, like how a real image flips upside down beyond the focal point. We also did an activity involving a candle flame, lens, and paper board all placed on a meter stick. The flame of the candle projected an image of the flame onto the board. It was interesting to see how the clarity and size of the image changed as the lens was moved further and closer to the lens. The lens was later altered so that the flame was projected through a pinhole.

Refraction Angles

Learning Goal 2.1- I can describe the phenomena of reflection, refraction, and dispersion of light with the ray model of optics.

This week, we began a new unit: ray optics. Our first activity was the gold rush worksheet, where we tried to find the fastest route between 2 points. My group found that in this case, a straight line would not be the fastest way between the points because of the 2 different terrains. After finding the fastest time, we then applied the same concept with a real model of an acrylic and light ray. I've struggled a bit with understanding Snell's Law, but I think Friday's worksheet somewhat helped. 

Unit 1 Project

Learning Goal 1.2- I understand where I am situated (physically) in the universe.
Learning Goal 1.3- I can describe the historical context and impetus for the development of natural philosophy.

For my project, I chose to write a research paper covering focusing on learning goals 1.2 and 1.3. The paper covers the historical background for scientific discoveries and achievements. I hope to compare different philosophers' viewpoints and further enhancements on similar discoveries, and also talk about how those discoveries are integrated into what we learn today. One topic I talk about is the discovery of lunar phases, which is often credited to Galileo; picture source is https://en.m.wikipedia.org/wiki/Sidereus_Nuncius#/media/File:Galileo's_sketches_of_the_moon.png.

                                                  

Earth's Circumference + Phases of the Moon

Leaning Goal 1.2- I understand where I am situated (physically) in the universe.

This past week, we learned about the different phases of the moon and how to measure the circumference of the earth. Beginning with the moon, I didn't find it too difficult to remember the stages: new moon, waxing crescent, 1st quarter, waxing gibbous, full moon, waning gibbous, 3rd quarter, and waning crescent. The only difficulty I had was differentiating waxing and waning. Later in the week, we measured the circumference of the earth using Nasif's model, which helped show the work of Eratosthenes regarding the curvature of the earth. We began by measuring the height and width of the sticks on the model, and using those numbers to determine the necessary angle (14 degrees). We then measured the distance between Alexandria and Syene on the model (30 cm) and set up a proportion to determine the earth's circumference based on the model. Then, we inserted the actual distance (843.6 km) in place of the 30 cm to determine the actual circumference of the earth. Our answer of 22, 000 km was about half off the actual circumference; this was because our angle of 14 degrees was incorrect due to inaccurate measurements of the height and width of the sticks. Similarly to last week, I noted the importance of accurate measurements.

Observing the Sun

Learning Goal 1.1- I can measure the passage of time through the motion and appearance of the Sun and Moon.

This past week, we used a pinhole camera to see an image of the sun, casted on to graph paper. We used the camera and the image to determine the angular size of the sun and measure its motion. We started by measuring the diameter of the image (7 mm) and length of the tube (760 mm) to find the angle of the sun, which was approximately 0.538 degrees. With the angle of 0.538 degrees and a time of 98 seconds for the sun to move a full diameter, we set up an equation to find how long it would take the sun to move 360 degrees. Our answer was 18.5 hours, when it should have been 24. This was because our time for the sun to move a diameter was incorrect as we had difficulty aligning our camera properly. From this experiment, I learned how to measure the angular size of the sun as well as how motion is seen through the passing of time. I also found this experiment to be a good refresher on trig functions.  Additionally, I learned the importance of accurate measurements.