UKERUB!

So we were learning about the technique "UKERUB" which is opposite of the BUREKU technique. So instead of breaking up a diagonal vector into horizontal and vertical vectors, we instead tried to find the vertical based on x and y axis lines! When using this technique, we are given distances in a certain direction such as Northeast, South, etc. It is a three-step process starting with drawing a picture! This is very important because then you can see the actual route travelled and makes it so much easier to solve when you know which vector you are trying to find! Then we make a t-chart of the x and y vectors (the distances). Then we have to add all vector components at the bottom of our t-chart! Once we do that, we can use the "ukerub" technique. Then we use Pythagorean Theorem to find the hypotenuse travelled and our SOHCATOA (either sin theta or cosine theta) to find the actual angle travelled in the direction!

We also learned about Free Body Diagrams which are pictures that we use, then draw the force/tension/weight/friction/and any other forces in certain directions they pull. We do NOT draw the forces on the original drawings. This goes with what we learned about Newton's Second Law that Fnet=ma, so the sum of all forces is equal to the mass times acceleration giving them a direct relationship. So for example and object on a table would have its weight pull downwards and have Normal force pulling direction upwards with the same force.

This is a picture of my small living room chandelier. It's held on by a chain hanging from the top of the ceiling. It would be balanced and there would be Tension pulling upwards while weight would be pulling in the opposite direction but with the same force!

Newton's Laws!

Newton has three laws of motion. 

The first law states that an object at rest (not moving) will stay resting until acted on by an unbalanced force. And that any moving object will remain moving in that direction with the same speed unless acted on by another unbalanced force. This means that objects in motion continue to do whatever they are until they are moved or stopped by another element. 

Ex. My water bottle is at rest standing up. When i hit it with my hand, the force applied would be unbalanced, causing the water bottle to fall over.

Newton's second law of motion is that force is equal to mass times acceleration. (Acceleration is produced when force acts on mass). These have a direct relationship so as the mass increases, so does the force. 

Ex. A filled water bottle would have more mass than an empty one right? So the filled bottle would need more forced applied to be knocked over. The left bottle was really easy to knock over because it was completely empty and there was barely any mass holding it upright. The other was heavier making me apply more force to tip it over.

Newton's third law states that "For every action, there is an equal and opposite re-action" so for every force, there is an equally sized force but in the opposite direction. 

Ex. If I pushed the bottle from the top, but didn't apply enough force for me to knock it over, it would come back with force towards me. 

Simple stuff guys! :]

Unit 4 Trig!

We had to apply some trigonometry to our physics learning by incorporating SOHCAHTOA into projectile motion and diagonals. Since we don't like using diagonals, we need to "BUREKU" them up into horizontal and vertical lines instead! We used Sine (opp/hyp), cosine (adj/hyp) and tangent (opp/adj). It's easy to find these angles because we can plug in the numbers into our calculators. The hypotenuse would represent speed(velocity) in meters per second. In order to find the horizontal and vertical velocities of an angle we would set it up based on which side we are finding the distance for! So if we were to find out the y measurement of a triangle (vertical), we would have to use Vo times sine theta. and to find x (horizontal) we would multiply Vo times cosine theta. We would also use our t-chart and plug in all variables to find time (VAT: V=Vo+AT) and range using DAT equation which is d=1/2 at^2 +Vot!
We also went over some more kinematics in our Flying Donkeys lab where we dropped a ball from the top of a slop and determined exactly (or very close to) where our ball would land by measuring the slope angle, distance, and height. Here are the results to that lab!

Unit 4

I decided to reproduce our little lab today at home, but without a lot of the technical supplies! I created a slope using a shopping bag and dropped the ball from the top. This creates acceleration making the ball travel faster each second. The table is about .5 meters tall so the distance on the y axis would be -0.5m because the origin (top of table) is 0m (original velocity). Gravity is always pulling so the acceleration would be -9.8 m/s^2. If i were to find the velocity of the ball i could plug in numbers to find the approximate distance it would travel and fall at the bottom of the table! When we were learning about projectile motion, I was really confused at first but as we did more problems and got into our lab, i started to understand how it worked! Its such a simple concept to learn and once you have it down, it stays! Drawing out what the situation/problem looks like helps a lot because then you can see the axis, direction, and draw out the item falling. Plugging in the numbers into the DAT equation is really easy so just follow the right equation and you end up with the correct answer!

Quarter 1!

My cousins (who are so cute) were playing this game where we would run onto a beach mat, and see how far we can make it travel once we land on it. We would run from any point we want but jump at the same point each time then land on a beach mat the same distance away, which is about 2-3 meters from the starting point. I think it was common sense that starting at a father point and running towards the start (accelerating) your speed would increase, thus causing you to land faster and have the mat go farther. If i were to set this up using a dt graph, the slope would be linear increasing each step forward, then once in the air there would be constant velocity until they hit the ground slowing down as they get further away. On a vt graph the line would increase in a straight line upwards then travel slower, so have the line decrease with time. The farther you start running, the more acceleration you get causing you to gain velocity/speed, then landing at a rast rate, but since the friction against the grass causes you to slow, you would still be accelerating but decreasing speed rather than increasing. A source of error could be improper placement of the mat, differences in weight, and inexact measurement. But in all, run faster, go father!

This goes a long with a lot of what we learned in kinematics with acceleration with motion. We learned about distance, velocity, original velocity, time, and units of each variable! We can find each one of these using the equations DVT, DAT, VAT, and VAD by plugging in the number we know and canceling out the units! We found out about gravity being about 9.8m/s and how objects at rest start with 0 m/s as their velocity. We also learned how to graph objects in three different ways, position and time (velocity), velocity and time (acceleration), and the area under a curve (displacement). SO many things have to do with physics in our daily lives! Its crazy!

Free Falling

So this is supposed to be a splash! When jumping off into water, it always seems to be more exhilarating to jump from high places rather than low areas! Today i learned from our Modern Galileo lab that if you were to fall from the same height as someone else, the rate at which you would fall would take the same amount of time, since the force of gravity is the same on both people. If you were for example jumping from a diving board and accelerated to travel up, you would speed up, slow down, stop for very short and travel in the opposite direction and with the help of gravity you would increase speed. You would accelerate down at the same rate you were forced up by the diving board. Gravity can be different though based on your location, which can cause some confusion when trying to graph and look at the constant acceleration. The acceleration or change in speed would decrease as you travelled up, but increase as you fell towards the water in uniform acceleration, which is equal increases in speed in equal intervals of time. Objects in freefall are objects under the influence of gravity, and acceleration=Ag and g is approximately 9.8m/s^2, which is always pulling downwards. Also, when we were doing the activity with the money and meter sticks falling, i figured out how to set up equations to easily solve for a certain variable, such as solving for time which is the square root of 2d/a in DAT equation. Then plug in the numbers to find the amount of time it would take! Distractions can obviously alter the times and decrease it because it takes longer for you to actually react to a situation when focussed on something else too! 

Acceleration

This is my friend Tyler and his board. As you can see really likes boogie boarding, so while out catching waves I realized that there's an increase in acceleration as the wave carries you through the water! Acceleration is the change in speed/velocity, whether it's increasing or decreasing. So it can be through increase in speed, decrease in speed, or change in direction. There are many factors that can affect the acceleration of the board, such as direction whether you're going straight, to the side, or stopping yourself. 
A (acceleration) is equal to delta v (change in velocity) over delta t (change in time), since it's based on velocity which speed in a given direction. It could be written as 1 m/s^2 because if you set up the equation you would end up with meters over seconds squared. He accelerated through the water by increasing speed as the waves got closer the shore, also accelerating when he turned back or changed directions in the water to either stop, or go back through the wave to avoid the rocks. I love the beach and Physics really has taught me to look at all the little things and to see that science is all around us!

This is Juliet (as you all know)! And my friend Jensen. We were all taking the bus to Ala Moana Center last Summer, which took about 30 minutes total; 10 minutes waiting for the bus to arrive, and 20 minutes actually riding it including the numerous stops it would come to. Our starting point would be the bus stop directly across from Punahou School and our ending point would be at Ala Moana Center's entrance near Nordstrom. If i were to graph this on an x(distance in miles) vs. t (time in minutes) graph, it would start off as a straight line since we would wait for a certain amount of time for the bus to arrive, then the slope would increase since we are travelling in a direction away from our starting point. At each turn, stoplight, and necessary bus stop, the graph would create a horizontal line (even if it's short) since it accelerates through the gas, brakes, and turning, but the slop would still increase with distance and time because of their direct relationship. Once it has reached the ending point (Ala Moana) the distance travelled would be about 1.5 miles. It would continue travelling its route, and then the slope would begin to turn negative since it is travelling in the opposite direction than before. It would reach the point at which it started, so the distance travelled altogether would be about 3 miles, but the displacement would be 0 miles because it has returned to the same spot.

Compared to walking, the times don't vary by much. If I were to graph walking to Ala Moana, the graph would start off with an automatic incline since there is no need for waiting or resting time, with the exception of crosswalks, since we would just travel straight there. We would be moving at a constant speed in a positive direction away from the starting point if we were to use the same bus stop as the origin of the graph. Travelling with constant speed will take about 30 minutes. Crosswalks and stoplights would alter the graph a little creating a flatline for a couple seconds, but the slop would then increase as we travel farther away from Punahou. Travelling back to Punahou would take the same amount of time and would create a similar slope to that of the bus, but a steeper one since the bus route is farther and in a different direction. Ending up at the bus spot outside of Punahou would still give me a displacement of 0 miles for both the bus and on foot. If I compared the bus time and walking time, they would take about the same amount of time (30 min, but their graphs would show up different with varying resting point and acceleration points.

Unit 2

In this video I walked back and forth across my living room. I started by my back table (starting position) and returned to the same spot after. Walking is a type of motion and since I started off resting, I accelerated twice: once when I started walking, then when I stopped after finishing my course. Acceleration is to start, stop, go faster, or go slower, so basically a change in speed or velocity. When I was walking, I accelerated forward to move, but then accelerated backwards in order to stop myself. The distance was about 4 meters total, 2 meters each way, but my displacement was 0m. Why? Because I ended up returning to the spot I started at! Distance is the total path length, and displacement is distance with direction. 

Unit 1

When my family and I were at the Excalibur hotel, my little brother played a lot of circus games there. As learned in Unit 1, accuracy and precision play a big part in winning these types of games. In this game, there was a catapult type of machine, where you would hit the leer and have a doll fly into a cauldron pot a couple feet away. The distance the doll would travel depended on how much force was exerted onto the machine and which area of the lever it hit, whether it was in the middle, end, or top. Accurarcy is the closeness to the initial target (where he aimed) and precision is how close the groupings are to each other (where the doll actually landed and how often it did so). My brother had figured out the right area to hit the lever and how hard to hit in order to get the doll into the pot. One of the causes of error could be the way the doll was placed in the catapult, but with consistant tries to the same spot he was able to win!

Intro

            My first name is pretty long so everyone just calls me Nalei. There are 5 people in my immediate family and I'm the middle child having two brothers, one older one younger, making me the only girl. I wish I would've grown up with a sister a lot of times, so my I have a lot of really close friends which I consider family! This would only be my 3^rd year at Punahou so I'm going to be a Junior! The past two years went by so fast for me, especially Sophomore year! Last year I was in Chemistry and I really liked it because there were so many labs practically one everyday, which was fun most of the time because it's hands-on kind of work and we always worked in pairs or small groups. I just finished Geometry, but I've found that I'm not so good at math, so Physics may be a little hard for me, although I'm up for the challenge! I'm hoping it won't be so terrible because the classes are really long and there's so much material to cover, but I know majority of the class already so that's a plus! I enjoy Science courses, which is why I'm taking Physics over Summer, so I can take another Science class during the year.

Those are 3 of my friends in my picture! It was taken last Summer, which I consider one of the best Summers ever! I love the beach! Love love love, so it was about every-other-day when I would go to the beach with my friends, and it wasn't always the same people, so that was really fun :)