Semester 1 Review

This semester we learned quite a bit. In unit 1 we learned about accuracy precision, metric conversions, the different types of graphs, graphing, and scientific notation. We focused on graphs and looking at graphs and then figuring out the relationships between the two variables. We also looked at equations of graphs. 

In unit 2 we learned all about scalars and vectors. We learned distance and speed are scalars, and that displacement and velocity are vectors. In this unit we mostly focused on velocity, how to find velocity, V=d/T, position vs. time graphs, velocity vs. time graphs and all of the graphing rules. 

In unit 3 our focus was on acceleration. We learned how to complete kinematics problems which involved the equations DAT, VAT & VAD. We also focused on throwing up balls and the acceleration a ball goes through when it is thrown up which is fast, slow, stop, slow, fast. 

In unit 4 our focus was projectiles. The problems were just like the ones in unit 3, but this time we had values on the x and y axis. The main rule for this lesson was that axis are independent. The problems were complicated at first, but once you got the hang of it they are good. We mostly worked with DAT for these problems. 

In unit 5 our focus was vectors. In this unit more than any we had to use math, trigonometry specifically. We had to use the bureku method and split up the diagonals, then use tan, sin & cos. We also learned about frictional force which is a force that opposes force or impends force. We learned what normal force is and how when we are on a scale that is what is measured. We also focused on newtons three laws, law of inertia, law of acceleration, and action reaction. For the problems in this unit we had to create diagrams, that is key and then from there we could get the answers. 

In unit 6 we focused on newtons second law. Fnet= ma. For problems involving pulleys we had to remember that the acceleration and tensions of the objects were the same because they are all on one string. We also learned about friction and how there are two types, static and kinetic. We learned about one more equation too, force friction=coefficent of friction • normal force. 

I enjoyed that almost every day in class we did something fun like a lab that involved physics but was enjoyable at the same time. The human pendulum, the pool projectile experiment and the slip n slide were some of the funnest. I also enjoyed how the classroom is always fun. I never feel uncomfortable or confused because I know I can always ask questions. 

Unit 5 & Unit 6 have been challenges of mine because of the normal force, friction and diagrams. The diagrams are what always stump me and they are the key to the answers. Another challenge for me was learning about acceleration. I also get confused whether acceleration is positive or negative. Other than those challenges, physics class has been fun, and I feel like I have been learning a lot!

Unit 6

Today's class was again like another math class. We focused on newtons second law, law of acceleration which states Fnet=mass x gravitational force. We went through multiple problems involving newtons second law. I learned that force and acceleration have a direct relationship and that mass and acceleration have an inverse relationship.  The first problem went over consisted of a "pulley," which changes direction of our force. The pulley had two weights attached at the ends and because of this we had to draw out two diagrams. Drawing a diagram is the first step that we learned we must do in any problem like this. The second step is finding the acceleration of the system. The acceleration of both diagrams is the same because they are attached by the same string. The third step is to choose oen mass to find T. The tensions of the two masses are the same because they are attached by the same string.
Next we went over elevator problems. For these problems we had to draw a diagram, and from this diagram we figured out our equations. Another thing that I learned to class today is that there is no normal force when the object is not touching a surface, that is why for one of the elevator problems when the cable suddenly broke, the force of the floor on the man in the elevator was 0 because there is no normal force when there is no surface.

Unit 5

Newtons First Law (stops because of friction

We continued our learning on unit 5 and force today. We learned the three newton laws and experimented with examples of all of them.
Newton laws
1) Objects in motion or at rest will tend to stay in motion or at rest unless acted upon by an outside unbalanced force.
2. The acceleration of an object is directly proportional to the net force on an object which the acceleration of an object is inversely proportional to an objects mass. (Fnet=sum of all forces in the axis)
3. For every force or action there is an equal and opposite force or reaction, equal in magnitude, opposite in direction.

Newtons Second Law ^ (Testing Weight/Normal force)

We did a few experiments to test each law. For the first law we learned that when we push objects, they stop moving eventually because of friction. For the second law we learned that bathroom scales measure your normal force and that normal= perpendicular to the ground. For the third law we learned that when two things collide they have the same amount of force inflicted on the two objects no matter the mass or size. In our spring scale lab we also concluded that mass and gravitational force is direct; when mass increases so does the gravitational force.

We also continued to learn about vector problems. We had to use trig to figure out some values. For these equations we have to know that the x direction values always equal each other, and the y direction values always add up. Frictional force is a force that opposes force or impends force.

Newtons Third Law (We have equal forces)

Unit 5 - Forces in Equilibrium

This picture represents what we learned in class. We learned a lot about triangles, vectors and trigonometry and to do all this we had to use our calculators a lot especially the sin, cos, and tan buttons.

Today's class was like a math lesson. It was all about trig. We started off my reviewing vectors.
Vectors are equivalent if they have the same magnitude and direction. 2 vectors and the resultant of the two vectors make a right triangle. By using an angle, and a side you can figure out the other angles and the other sides of the triangle. You can figure out the sides and angles of the vector made triangle by using TAN, SIN & COS

tan= opposite/ adjacent
sin= opposite/ hypotenuse
cos= adjacent/hypotenuse

 We learned a few rules for vectors

1) Break up all diagonals=Bureku
2) Add all values together to get the sum of resultant (axis are still independent)
3. Ukerub- make 2 vectors into one. take x and y sums and create a new vector

This photo represents what we learned today about forces. 

We also learned about forces.
 a force is a push or pull (vector quantity, has direction  & magnitude.
Forces in Equilibrium (balanced force)
- objects that are not accelerating are in equilibrium
      •means they are not moving faster or slower or turning.
A normal force is a supporting force that is perpendicular to the surface the object is on. We learned one of Neutons laws. Neutons first law or the law o inertia states objects in motion (or at rest) will tend to stay in motion (or at rest) unless acted upon by an outside unbalanced force. 

Unit 4

On monday we continued to learn about unit 4 and projectile motion. The picture above is a great example of projectile motion. My friend is jumping off the pole and if I calculated the height of the pole from the water, and the speed she is moving at, I could figure out where she would land in the water. I could figure out this out by using dimensional kinetics which we have learned all about in this unit. In  types of problems we are using x and y distances, accelerations, times, velocities and original velocities.  It takes a lot of organization and the use of DAT, VAT & VAD. For most of these problems the X acceleration is 0 m/s2 and the Y original velocity is 0 m/s, but it really depends on the problem. 

Air Rocket Lab

On monday we also played with rockets. Rockets are a great example of projectile motion. We shot up our rockets using 4 different caps and doing 3 trials per cap. Then we decided which cap was the most consistent. Using the times from the most consistent cap we figured out the average time and initial velocity. Mr. Blake gave us an angle that we would be firing with, we then used our angle and trig to figure out the distance that our rocket would land at. It took a lot of work, organization, and math but my group finally came up with a distance for where our rocket would land. When we went to test our distance, we were very wrong though. I think some errors in our experiment might have been organization, direction of wind, our gas pump and our white cap which was very broken. 

Unit 4- Projectile Motion

Unit 4
In class today the most important rule that we learned was axes are independent. This rule turned out to be most helpful when we did problems including projectiles like the experiment in the left picture. Our experiment was to shoot a ball out of a projectile and try to be precise and accurate with the place that the ball hit the ground. We had to use the axes are independent rule when we had to figure out distances. We then were given a test height and using the velocity of the cannon that we had already calculated has to mathematically figure out where we should place the paper bulls eye. My group was pretty close when we tested out our distance, but we had a few errors like angles, the position of our projectile cannon and not using the same ball every time.  It was a really fun activity.

We also did a fun pool activity today. A few of my classmates jumped in the pool and we video taped them doing it. Then we took the video and put it up in logger pro. In logger pro we graphed the persons acceleration, velocity and position and it was really interesting to see how the person moved. 

1st Quarter Review

Today:

In class today for our lab practical we dropped a thin plastic sheet through a motion detector and examined it's  position vs. time and velocity vs. time graphs. The relationship of the position vs. time graph was squared and the relationship of the velocity vs. time graph was linear. We learned about this yesterday and that a curved position vs. time graphs gives you a linear velocity vs. time graph and acceleration. 

These two pictures of people running is a good example of what we have been learning this first quarter. We learned all about speed, velocity, distance, acceleration and movement. If I wanted too I could graph all of these runners using the great knowledge that I have learned this quarter. 

Unit 1 

In unit 1 we learned about: 

Accuracy- closeness
Precision-consistency 

Qualitative- qualities measurements

Quantitative- numbers measurements

We learned about the 5 different graph shapes no relationship, direct, inverse, exponential, square root and all of their mathematical equations. 

Kilo=1000 Centi=.01 Mili-.001
D= V/ T

Unit 2

In unit 2 we learned about:

Scalar (a number that has magnitude)- distance & speed 

Vector (has magnitude and direction)- displacement and velocity 

Velocity-average speed

Graphing Rules

1. The slope of a position vs. time graph is velocity 

2. The slope of a velocity vs. time graph is acceleration

3. The area under the "curve" of a velocity vs. time graph is distance.

We learned how to tell on graphs when two objects are moving which object is moving faster and which object has moved further. You can figure these out by if which slope is steeper, and which is longer on the x axis. When the lines of a position vs. time graph is direct, then the line of a velocity vs. time graph is a straight horizontal line. 

Unit 3 

In unit 3 we learned about:

A= V/T  Units: m/s2

Curved position vs. time graphs give you acceleration

DAT, VAT, & VAD

We learned how to do kinematics equations and which steps to follow: Write down the question, write down givens, sketch, choose equation, plug in and box your answer. 

We went over lots of graphs having to do with velocity and acceleration. We learned how to go from a position vs. time graph to a velocity vs. time graph to a acceleration vs. time graph. 

Unit 3

These two photos show a glimpse of what we did in class today. The focus of our class was on acceleration and using acceleration in real life situations. One of the real life situations that we experimented with is the one shown in the pictures above which is dropping two different sized balls. The question that was asked when we dropped these two balls was would the large ball be faster, would the small ball be faster, or would they be the same. We soon found out that they were of the same speed, even though one ball was significantly larger. 

We also went over multiple kinematics questions and I were tested on challenging problems. By using DAT, VAT, & VAD we were able to complete these problems. I found out that drawing a diagram is very helpful. I learned that for most problems the key is acceleration, as for DAT, VAT, & VAD acceleration is something you always need to know to figure out another variable. I also learned that in most problems acceleration is 9.8 or 10 m/s2 down . This is the acceleration for anything while on earth. 

Graphing:  We graphed cars going down ramps, and graphed balls being thrown up in the air. 

From these graphing exercises I learned that going up a slope means the object is slowing down, going down a slope means the object is speeding up. When a ball is thrown up it's acceleration is fast, but then slows and stops at the top, then goes down faster until it stops in someones hands. 

Extra Credit: Teaching my parent

Unit 3- Uniform Acceleration

As a carousel starts to spin it gradually picks up speed, or accelerates. 

Acceleration= a change in velocity per unit of time 

A= V/ T Units= m/ (s)2

In Unit 3 we learned a lot about acceleration. I could graph the position, velocity, time and acceleration of a carousel. 

We also learned a few equations that can help us to figure out distance, acceleration, time, or velocity. 

Equations: 

d= 1/2(a)(t)2 + (Vo)(t)

v=Vo + (a)(t)

(v)2=(Vo)2 + 2ad 

We also learned steps to help us use these 3 equations

1. Write down the question

2. Write down the givens

3. Make a sketch. 

4. Choose the equation. 

5. Plug in

6. Box answer

7. Check to make sure your answer makes sense. 

All of this information will help if you ever needed to figure out the velocity that the carousel is moving out, the distance that one of the moving animals has traveled, the acceleration the carousel has picked up, or the time that it took for the carousel to go around. 

Today we conducted a experiment using skateboards. We conducted 2 trials on 2 different types of moving objects, a skateboard and a "danger" board. We timed each 5 meters as the boards passed and then graphed the results.  By looking at the graph we noticed that acceleration increased as the skateboard's distance increased down the slanted surface. 

From the results we also figured out one graphing rule: curved position vs. time graphs give you acceleration. 

Unit 2-Kinetics

My picture relates to what we learned in unit 2 because we learned about motion. When people snowboard or ski they are in motion. Going down the slope their velocity or average speed changes as well as their distance and displacement. 

Snowboarders and skiers accelerate as they move down the mountains. 

Acceleration- a change in velocity per unit of time, any time you change your velocity . You can find the acceleration of a moving object by using the formula: A= V/ T

Snowboarders and skiers move quickly down mountains, sometimes skiers are faster some times snowboarders are faster. You can figure out the speed and position of skiers and snowboarders at different times by using graphing and equations. 

The slope of a position vs. time graph is velocity. Position vs. time graph tell you where you are (position.)

The slope of a velocity vs. time graph is acceleration. This type of graph tells you velocity. 

 This information could be helpful when you need to know where a skier or a snowboarder was at a certain time. If the snowboarder has a velocity of 30 mph and the skier has a velocity of 35 mph then you can conclude that the skier is quicker. On a graph the skiers slope will be steeper. 

The area under the curve of a velocity vs. time graph is distance traveled (displacement). If you look at a velocity vs. time graph you can figure out the displacement of a moving object without using an equation. 

Unit 2- Kinematics: The Study of Motion

This photo represents unit 2 because in unit 2 we learned all about motion, and in this photo my friend is walking, and in motion. We learned about how all motion is relative and that motion depends on the object and what it is relative to. For example, my friend in this photo appears to be walking fast relative to me, who is standing still. Relative to a person who was walking faster than her, she would be considered slow.
 Scalars are a number that has magnitude. Ex. My friend is moving 8 meters.
Vectors have magnitude and direction. Ex. My friend's vector is that she is moving 8 meters towards the street. We learned about how vectors have displacement. Displacement is different from distance. Distance is the total length of the actual path. Her distance would be 16 meters. Displacement is change in position. For example my friend started where I was standing, and walked to where she is standing in the picture which is 8 meters away. If she came back to exactly where she started her displacement would be 0, because she would be going back to exactly where she started. To the place she is in the photo is positive  coming back to where she started is negative, so the 8 m cancel each other out and result in 0.
Instantaneous Speed- the speed you are going at any given distance. My friends speed could be 10 mph, but its the speed she is traveling at right then.
Velocity- average speed, speed with direction. I can find my friends average speed by using the formula V= distance/ time.

Unit 1

In Unit we learned about accuracy, precision, different types of graphs, pendulums, scientific notation, and dimensional analysis.

Accuracy- the closeness of a measurement to the actual value

Precision-the consistency of measurements repeatability of results
The picture of the bull eyes represent accuracy and precision. The first bulls eye shows high accuracy and high precision because the darts hit the middle and hit the middle a bunch of times. The middle bulls eye shows low accuracy and low precision because the darts didn't hit the middle and didn't hit the same spot. The last bulls eye shows low accuracy because the darts didn't hit the middle, but high precision because they hit the same spot every time.
The second picture shows a bunch of different graphs which were major in our learning these past two days.
The first graph shows how the two variables have no relationship. As x increases, y remains the same.
The second graph shows how y is directly proportional to x. As x increases, y increases proportionally.
The third graph shows how y is inversely proportional to x. As x increases, y decreases
The fourth graph shows how y is proportional to the square of x.
The fifth graph shows how the square of y is proportional to x. (square root)

We also learned about dependent and independent variables.
 X is usually the independent variable and Y is usually the dependent variable. Y depends on X.

Accuracy, precision and the different graphs have been very major in our few days of learning of physics.

• My name is Candace Chan. I am a Junior and I live in Diamond Head. I was born in Houston, Texas and after 6 months moved to Hawaii.  I've been going to Punahou since I was in kindergarten. I have a older brother, who graduated Punahou two years ago. He is now a sophomore attending Southern Methodist University in Texas. I really enjoy going to the beach, being in the sun, running, swimming, and taking pictures. 

•Freshmen year I took biology during the summer. I struggled with the long hours of bio, but over time it became a really fun! Sophomore year I took chemistry, which surprisingly turned out to be one of my favorite subjects, although stressed me out a lot and I disliked because of the long one and a half hours classes. I thought chemistry was really interesting and didn't pretty well in the course. 

•The math course I will be taking next year will be Alg 2/ Trig (regular). 

•I am very interested in science, and exploring the option of becoming a doctor when I am older. I am taking this course to better my understanding of science and see if I enjoy physics which will help me to decide my career choice. I hope to obtain some understanding of what type of science I like the best and this information will help me in the future for college and career. I also wanted to obtain a easier schedule for next year, because physics is a year course I can get it off my plate and hopefully have a cruiser schedule next year. 

•The story behind this picture is that these are my two best friends. We do everything together and I wouldn't be who I am without them. This picture was taken recently at the Sheraton Waikiki. This day was a super fun day for all of us, we went shopping, ate, went into the pool and the beach. This pool is the infinity pool and it's super nice. We stayed there for a while and watched the sunset. This photo represents me because it shows how I love hanging out with my friends, and I love being in the water, at the beach and outside. It shows me in a swimsuit, which is what I usually am in during the summer. It also shows Diamond Head in the back, which is where I live.