Saturday, December 10, 2011

"What I learned in 1st Semester"

This semester I learned a lot!! The first unit we learned about was Kinematics (1-dimensional and 2-dimensional).  I learned that kinematics is the study of motion.  This is the basics of physics.  After we learned about kinematics, we learned a little bit of graphing that goes deals with kinematics.  The next unit was Forces and Motions. In this unit I learned Newton's 1st, 2nd, and 3rd laws of motion.  I learned that a newton is in units of kg m/s^2 and that weight = mg. Also in this unit we learned about pulleys and because it has one string, that means there is one tension.  Momentum was the next unit we learned about.  I learned taht momentum is a vector that is calculated by multiplying mass times its velocity (units: kg m/s). The law of conservation of momentum is that momentum cannot be created nor destroyed, it can only change forms, so therefore, momentum in equals momentum out.  Similar to this law of conservation, I learned about the law of conservation of energy which basically stated that energy in equals energy out, in the our unit of Work and Energy.  I learned much information this semester and many equations.  All this information and knowledge I learned was written down in my physics notebook so that I will never forget. :)

Sunday, December 4, 2011

DO WORK SON!

This week we learned about work and energy.  Work is activity involving effort to achieve a result.  To find work you can multiply the force on the object by its displacement.  The units of energy used is Nm, also known as Joules.  Work = the change in energy.  According the the law of energy, energry cannot be created nor destroyed; it can only change forms (in an isolated system).  The energry of position is an object's potential energy.  You can calculate an object's gravitational potential by multiplying its mass by the gravity by its height.  After learning about work and energy, it reminded me of this weekend.  My mom and I were sitting at the table and she asked me to pass her my pencil case.  I was too lazy to pick it up and hand it to her, so I slid it across the table.  I pushed my pencil case about 1/2 a meter.  If it took a force of 3 N to push the pencil case, the work I would being doing would be 1.5 Joules.  I'm glad I got to learn about Work and Energy this past week, so now I know how to what work and energy is and how it is applied.

Sunday, November 27, 2011

Egg Drop Lab...SUCCESS :)



This week we did our Egg Drop Labs! I found this to be a very fun, interesting, and yet kind of challenging experiment to do because Kawai, Lydia, and I weren't 100% sure if our egg was going to survive! We used a 33 cm shoebox as our device.  We glued lots of cotton balls to the inner surrounding walls of the box.  After the box was all cushion-ized, we took a smaller box and glued cotton balls into it. This small box would be the object that held our egg in place.  When we received the egg, we wrapped it in black felt and taped it so that it was secure.  Once we were finished wrapping our egg in felt, we placed it into the small box and closed it.  We then put bubble wrap between the cotton balls on the inside of the bigger box and the bottom of the smaller box. We taped the small box to the shoebox.  We closed the lid of the shoebox and taped it so that it would not fly off during the drop.  If you watch the first video above, it shows how our egg was dropped.  In the second video, you can see that our egg survived the fall!  The reason why our egg survived was mainly due to the cotton balls.  We chose to use cotton balls because we knew that it would absorb the shock of the fall.  I really liked this lab because it was like a mini project and there was a little bit of suspense right before our egg was dropped.  I also liked seeing the various devices that the other groups created.  After all the eggs were dropped I came to realize that this lab wasn't as challenging as we made it to be.  One group had a very simple yet effective device.  They had three sponges.  They cut a whole in the middle of one of the sponges just enough for the egg to fit in.  After placing the egg in the whole, the surrounded the sides with the other two sponges (one on each side).  They then rubber-banded the three sponges together and dropped it! To me, this was the smartest device of them all because it was light in weight and it had LOTS of cushioning which would make the contact time of the sponge and the ground a lot longer than a shoebox would.  But, in the end, I'm just glad our device worked and our egg survived.:)

Sunday, November 20, 2011

MOMENTUM!


I finally understand what momentum is and how you can calculate it.  Like I've mentioned in previous posts, momentum is calculated by multiplying the mass of the object times its velocity.  For example, the picture above is of my eraser.  Let's say that this eraser was 2 kg (a very heavy eraser).  If I were to throw the eraser and the velocity it was moving at was 2 m/s, I could then calculate the momentum of this eraser.  The momentum would be 4 kg m/s because I multiplied the mass by its velocity.  We use momentum in our everyday lives.  I am glad I know how to calculate momentum now!  I'm glad I learn something new in Physics everyday :)

Sunday, November 13, 2011

More Stuff on Momentum

This week in Physics, we learned more about momentum.  On Wednesday we were suppose to do a lab about collisions to help us learn more about momentum, but I was sick on that day, so I'm not exactly sure how to explain anything about collision.  But, I can explain a little bit about the Law of Conservation of Momentum.  This law states that momentum cannot be created nor destroyed, it only changes forms, momentum in then will equal momentum out.  From this week, I learned the momentum is a vector/  To find momentum you must multiply the mass of an objec by its velocity (P = mv).  The units we use in this equation are kg m/s.  I also learned about impulse and how it contributes to momentum and force.  Impulse is the change in momentum (delta P).  This is then plugged into the equation of force, which equals the change in momentum/change in time (delta P/delta T).  This is what I learned this week in Physics.

Sunday, November 6, 2011

My Thoughts on Momentum

Our next chapter we will be covering is momentum.  In order to begin this new unit, Mr. Blake wanted ut to make our blogpost about either what we think momentum is using our own personal knowledge, or doing research on it.  Because I don't really know anything about momentum, I did some research.  I first looked up the definition of momentum and dictionary.com gave me: "the force or speed of movement of an object".  I then looked in our textbooks for more answers.  The first thing in the textbook about momentum was linear momentum.  Linear momentum is defined as the product of the mass and velocity of an object.  The example it gave me basically said that if you catch a fast enough light-weighted ball and compare it to catching a heavy, slow moving ball, then you will move with the same speed.  This helped me to learn a little about momentum.  Before this small research, I only knew how to use the term "momentum" in speaking, but I never really knew what it was.  Now I know something about it!

Sunday, October 30, 2011

Friction!

This weekend, I had to move a couple of these big boxes from my living room into the office.  My living room floor is covered in carpet.  The boxes were way to heavy to carry by myself, so I decided to push them.  Although I am not exactly sure what the precise amount of the forces acting upon the boxes was, I do know that the forces that were acting upon it was weight (mg), normal force, the force I used to push the boxes, and also friction.  There was friction because the boxes were on top of the carpet, causing an opposing motion to my force exerted on the boxes.  Many times in the past I have pushed objects across floors, but I never really thought of why it was harder to push things across certain types of surfaces.  I now know that friction is an important part of motion.

Sunday, October 23, 2011

Force

In Physics, we learned about force.  A force is a push or a pull.  This week we learned  about how forces affect objects.  In learning this, we used free body diagrams.  In the picture above, there is my contact solution box resting on my dresser.  This box can stay at rest because it is balanced and no outside forces are acting upon it.  The forces which make this object balanced are its own weight (mg) pushing down and the normal force (N) pushing up.  These two forces equally pushing against each other is what makes the object balanced.  Right next to my picture of the box at rest on the dresser, there is my free body diagram.  Free body diagrams (FBD) helps us to see the forces and how they are affecting the object.  There are two arrows in my FBD, which are the weight and the normal force.  This is another way of explaining how the object is balanced.



Sunday, October 16, 2011

Newton's 1st Law of Motion

This week, we learned about forces and motions.  One thing I remembered the most from this week's lesson was Newton's 1st Law of Motion.  This law states that "objects in motion [at rest] will tend to stay in motion [at rest] unless acted upon by an outside, unbalanced force".  This weekend I went to support our football boys at their game against Punahou.  When the quarterback threw the ball in the air, it reminded me of the Newton's 1st Law of Motion.  After watching the ball being thrown, seconds later, it landed in another players' hands.  Seeing this, I thought to myself, "Wait a second...objects in motion don't always tend to stay in motion!" Instead of the ball staying in motion in the air forever, it dropped.  Confused, I rethought the situation over.  I then realized my mistake...I had forgotten about the outside, unbalanced force and how it affects objects in motion.  So, it was because of gravity that the ball dropped and eventually stop moving.  Gravity is an example of an outside, unbalanced force mentioned in Newton's 1st Law of Motion.  After the game on Saturday night, I was glad that I was able to incorporate some Physics into the game because I know that when I can relate things to real life situations, I tend to learn better.
...by the way, Congrats on the win Warriors! :)

Thursday, October 6, 2011

Sunday, October 2, 2011

2-Dimensional Kinematics

In class, Mr. Blake taught us the BUREKU Technique.  Mr. Blake doesn't like diagonal lines, so in order to find the velocity of the diagonal line he must...wataaaaa!...break the diagonal line into a horizontal and vertical line.  The BUREKU Technique makes life much, much easier.  We also learned about SOH-CAH-TOA this week.  SOH-CAH-TOA is used to find the hypotenuse, opposite, or adjacent variables of a triangle.  As you can see on my picture, there is a triangle with the labeled parts.  The hypotenuse is the diagonal line of the triangle, the adjacent line is the line that is inline with the angle given (marked with a curved line), and the opposite line is the line opposite of this same angle.  To figure out lengths of these lines, we are given 3 different equations:
SOH- Sin = Opposite/Hypotenuse
CAH- Cos = Adjacent/Hypotenuse
TOA- Tan = Opposite/Adjacent
You must plug in the right equations to fit the situation to find your values.  These are some ways to solve for 2-Dimensional Kinematics!

Sunday, September 25, 2011

Equivalent Vectors

In Physics, we use vectors as measurements.  A vector quantity has magnitude (size & unit) and direction (N, E, S, W).  Another way of remembering vectors is "how much and which way".  Velocity is an example of a vector because it tells how fast an object is going and in which direction.  In the picture above, there is two columns; one of an example of an equivalent vectors, and the other is an example of a non-equivalent vectors.  The reason the left column arrows are equivalent to each other is because they both are pointing North and are relatively the same size.  In the right column, we can tell that these two arrows are not equivalent vectors because first of all, they are pointing in two different directions, and second of all, the green arrow is shorter than the pink arrow.  A vector is only equivalent to another vector when both its' magnitude and direction are the same.

Sunday, September 18, 2011

What Goes Up, Must Come Down

This week, we did the Ball Toss Lab.  When Coach Chris showed us an example of what we were doing in the lab, he took a volleyball and threw it up 2 meters and then caught it at the same level he threw it from.  This reminded me of when my friends and I were trying to capture a picture of us jumping together. Coach Chris taught us that when an object is thrown in the air, its velocity goes slow, fast, stop, slow, fast.  This weekend I was just looking over my pictures and I remembered when we were all jumping in the air! It made me think that when we were jumping that we started off slow, then sped up as we got to the top, and then stopped in the air, and as we came down it went slow, and then fast as we hit the floor. This Ball Toss Lab helped me realize that whenever something goes up, it must come down, but when it is in the air, it has different velocities.

Saturday, September 10, 2011

Position vs. Time

This week in Physics, we did a lab that once again dealt with kinematics.  In the lab, we studied how motion worked in using a Motion Detector.  From using the Motion Detector, I learned that when an object stays in the same place for a certain amount of time, then the graph shows a line with a slope of 0.  When an object moves in a forward direction, the graph shows a decreasing slope.  When an object moves in a backwards direction, the graph shows an increasing slope.  So, in other words, I learned that the direction in which an object is moving and the time it takes to move that certain distance affects the direction of the graph.

Wednesday, September 7, 2011

Direct Relationships

Last week, we did the Physics Olympics Lab.  In the lab, we did 3 different activities: bunny hop, posture practice, and a gentle jog.  In all 3 events, a person in our group was timed to see how fast they could go for a distance of 50 m.  In the lab, I learned that position and time have a direct relationship because after all our data was collected, the graph was a straight line.  That means as time went on, so did the distance.  Kinematics relates to the real world because it is the study of motion and we use motion in our everyday lives.  A real world example of a direct relationship is the speed of a car and its distance.  As the speed of a car increases, so does the distance (and vice versa).  Learning about direct relationships has helped me to more about kinematics and it gave me better understanding of how things work in motion.

Sunday, August 28, 2011

Kinematics

Kinematics is the study of motion (which includes distance, scalars, vectors, displacement, speed, velocity, instantaneous speed and average speed. Today I decided to do my homework on the living room floor.  I took all my books and papers to the living room and laid them out and began to work.  As I came to my economics homework, I realized that the assignment was to make a poster, but I didn't have any construction paper or markers with me! So, I stood up and walked down the hall and up the stairs to my bedroom to grab some construction paper and markers, and then I walked all the way back to where I was working.  The total distance traveled was about 120 feet.  Distance is the total path length (how far).  But, even though the distance traveled was 120 feet, my displacement was 0.  Displacement is how far you went in relation to your starting point.  Going all the way to my room and back made my displacement 0 because  I did not move anywhere in relation to my starting point.  Kinematics is displayed in our everyday lives, whether its running, or walking, or maybe even driving.  Kinematics is important to learn because it can tell you many things about motion.

Sunday, August 21, 2011

Physics in the Real World


This assignment was to find something that relates to the unit in Physics that we are learning.  In class, we learned about various relationships between variables.  I took a picture of my shoes to signify how running and how our bodies react is an example of a relationship between two variables.  Running (or at least walking) is an exercise that everyone does on a daily basis.  When people increase the speed at which they are running (or walking), their heart begins to beat faster.  As they slow down their pace, the heart begins to relax more and starts to slow down.  As the speed of running increases, the pace at which the heart beats also increases (and vice versa).  Through this assignment, I have learned that we use Physics in our everyday lives!

Friday, August 12, 2011

A Short Introduction :)

Hello! My name is Melody Masutani, and I go to Kamehameha.  I have been attending this school since the 7th grade.  Some things I like to do include playing volleyball, hanging out with my friends, laughing, going to the beach, riding roller coasters, eating, sleeping, pooping, and admiring Coach Chris as a role model. I have 2 brothers, 1 sister, 2 nieces, a mom & a dad, and 2 golden retrievers. I love my family very much because they are always there for me! Weeee :) Anyways, in middle school, I had Ms. Maunakea & Mr. Kroessig as my science teachers.  My freshmen year I was in Biology with Mr. Hutchison, and my sophomore year I had Ms. Higa as my Chemistry teacher. And, as of now, I have the bestest, most funniest, cooliest, awesomest teacher in the Physics world...the almighty, Coach Chris.  This year, I am taking Pre-calculus with Mr. Agpoon.  In Physics, I hope to learn more about whatever it is we learn in Physics.... In conclusion, I chose this photo of me and my brother when we was "bebehs" because I love him so much.