Blog 17 - What I learned in S1

In this first semester of Physics, I have learned many things. Out of everything I have learned the thing that stands out the most to me is the equation d = vt. Like in this picture, I'm riding in a car. if we were traveling at 25mph for 5 seconds on this street, you could figure out the distance by converting 25 mph to m/s, then multiplying that by 5s. This was the very first equation I learned in physics, and I will never forget it. The entire Q1 was pretty much dedicated to the study of Kinematics (study of motion). Here are some other things I have learned throughout the semester.

Distance - total length

Scalar - Quantity w/ magnitude

Magnitude - muchness

Vectors - scalar + direction

Displacement - distance from starting point

Speed - distance covered per unit of time

Velocity - speed + direction

Avg v - Total distance / total time

Area under curve of v/t graph = distance

When an obj is thrown up and caught @ same level, Vi = Vf but in opp. direction

weight = mg

What happens on x axis stays (or for y axis too)

Force - push/pull

Inertia - obj.'s capability to continue in state it's in; directly proportional to obj.'s mass

Fnet = ma

Pulleys change direction of force

1 string, 1 tension

P (momentum) = mv

Impulse = change in P

Slope under F vs time graph = Inertia

Work = force x displacement; change in energy

PEg = mgh

KE = 1/2mv^2

Power = work/time

Area under F vs d graph = work

Blog 16

This last week of Physics, we have started the Unit about energy. Energy can be measured in Newton meters, or Joules. A joule is equal to: (kg x m/s^2 x m). By the law of conservation of energy, energy cannot be created nor destroyed; it only changed form. This is just like how momentum is conserved. However, this is only true in a 100% efficient system. For example, energy from the wall outlet runs through my lamp in the form of electricity. This energy changes form as it enters the lightbulb as light. As the light continues to emit, this energy is released into the atmosphere as heat, and so forth.

Blog 15

In this last week of Physics, we all participated in the "Egg Drop Lab". In this lab each group became independent and had the task of creating an Egg Drop Device with a purpose to protect the egg from damage after dropping it off the top of Akahi. My group's device was fairly simple and consisted of fairly common household materials. It starts with a sandwich sized ziploc bag filled with pillow stuffing. This is where the egg is placed. It's left open so upon impact the cushion can compress (and the air has somewhere to exit).This ziploc bag is then placed into a plastic bag filled with crumpled pieces of paper. It was placed on the very top so upon dropping the paper would absorb some of the impact. Underneath the paper balls (but still in the plastic bag) was a sealed ziploc bag filled with water. We chose to do this as another measure of absorbing impact. As it hits the ground, the force will be directed to the sides of the ziploc bag as the water bursts out of it. This ziploc bag also served well making our device bottom-heavy so the wind didn't man handle our device. This allowed our device to drop how we intended it. We chose these materials because they were common and inexpensive.

Blog 14

In this week of Physics, we have gained a deeper understanding of momentum. There are two types of collisions: elastic and inelastic. An elastic collision is a "bouncy" collision where the two colliding objects repel from each other. An inelastic collision is a "sticky" collision where the two colliding objects stick together and form one mass. For example, if I were to slap these two velcro pieces together, they would stick together, thus being an inelastic collision. But if I were to roll two rubber balls together like in my previous blog, they would bounce off of each other, thus being an elastic collision. I have also learned that impulse is the change in momentum.

Blog 13

After last week's physics classes, I have concluded that momentum is equal to the product of an object's mass and velocity. There's no specific unit for momentum, simply "kg m/s". In this picture, a small, multi colored ball is stationary while a larger, blue ball is rolling towards it. According to the law of conservation of momentum, momentum cannot be created or destroyed. This means that the larger ball's momentum didn't come out of no where. Before it was at rest like the small ball, but when I pushed it and increased it's velocity, I simply transferred momentum from my hand to the ball. Also, when the larger ball will come in contact with the small ball, the momentum will transfer over to the smaller ball. Since the smaller ball's mass is much less, but the momentum is the same (ignoring friction), the smaller ball will travel at a higher velocity than the higher ball did.

Blog 12

For this Physics blog post, I will be writing about momentum. I always thought of momentum as what inertia is. Inertia is an object's capability to continue in the state that it's in. Inertia is also directly proportional to the object's mass, so things with a greater mass have a greater inertia. After looking up momentum, I found that it's the force/speed of movement, measured as a product of an object's mass and velocity. From this I can conclude that both an object's mass and velocity are directly related to its momentum. For example, when I was running on the beach, you could measure my momentum by finding my velocity and multiplying it by my mass. If I were to run faster or if my mass was greater then my momentum would increase. If I were to slow down or if my mass was less then my momentum would decrease.

Blog 11

In this last week of Physics, we learned more about tensions and pulleys. Pulleys are objects that changes the direction of a force. In this picture, although there are no pulleys, there is a tension. In this picture, my dad's Blazer is pulling my uncle's tow-truck with a string. In class I have learned the saying "1 string, 1 tension". This means that if there's 1 string, there's 1, equal tension. That means that the tension pulling on my dad's blazer and the tension pulling on my uncle's tow truck are the same, equal tension. Also, if I wanted to find the acceleration of either vehicle, I would just find the acceleration of "da whole ting" because they are the same.

Blog 10

In our everyday lives, there are objects everywhere around us. On each of these objects, there are forces acting upon them and go on unnoticed. For example, look at this tiny skateboard. One force acting upon it is its weight, or mass x gravity (mg). This object isn't moving, thus it isn't accelerating. With that said, that means that this object is at static equilibrium. Another force acting upon this object is the normal force (N) which is from the surface it's sitting on, (in this case the carpet). Friction, or the contact force between two objects also exist between the skateboard and the carpet.

Blog 9

This week of Physics, we have been introduced to "force". Force is a push or pull. There are two types of force: contact, and at a distance. Contact force is a force that uses a physical contact between objects. For example, if I push my chair across the room, I am providing a contact force because there's physical contact between me and the chair. The other type of force, at a distance, is a force that has no contact. One of the most obvious at a distance forces is gravity. So, going back to the chair. I am providing physical force, but that's not the only force that is acting upon it. Gravity is also there acting upon it, pulling it down to the ground and keeping the chair from floating all over the place.

Blog 8

Last week of Physics, one of the most important things I learned in class was the "Vegas Rule". The Vegas rule is: whatever happens on the x-axis, stays on the x-axis. This saying is also the same for the y-axis. What this means, is that the x and y axis of an object are independent and don't affect each other. For example, if I were to throw this pool stick horizontally on the x-axis with no force directed to the y-axis, the  time it would take to fall would be the same as if I just dropped the pool stick directly from the same height. This is because what happens on the y-axis stays on the y-axis. Just because I would throw the pool stick horizontally on the x-axis, it doesn't affect the velocity, acceleration or anything dealing with the y-axis. Although it would be traveling on the x-axis, it would also be accelerating down the y axis with the same velocity as if it were directly dropped. The only difference is, the one being dropped is not traveling on the x-axis.

Blog 7

During this past week of Physics, we have learned a bit more about vectors and scalars. A vector is comprised of both a magnitude, or the "muchness", and a direction. Scalars on other hand, are just like vectors, except they only include a magnitude and not a direction. For example, in my picture, you could think of the two spearguns as two scalar quantities. You could see that the gun on the top is relatively larger than the one underneath, thus having a greater magnitude. However, you could also see these two spearguns as vector quantities as well. Since the magnitude is the length of the gun, all you have to do is add on the direction. For this example's sake, if you consider the top of the picture North, then these vector quantities are pointing West with either a larger (top gun) or a smaller (bottom gun) magnitude.

Blog 6

In this past week of Physics, we have did the ball lab. In this lab we recorded a person tossing a volleyball up as well as catching it when it comes back down. We have studied 3 graphs of this motion. A distance vs. time graph, velocity vs. time graph, and an acceleration vs. time graph. In this picture, I am basically applying the same concepts that we were experimenting with in the lab. I have learned that if you throw something up with a "x" velocity, the moment it returns to its origin it's traveling at the same speed as it's initial speed, but in the opposite direction. So as I threw my sock up into the air, when it reached the point I released it, it was traveling at the same speed. Then, it continued to accelerate faster as gravity pulled it down until it came to a complete stop when it hit the ground.

Blog 5

Speed can be defined as the distance an object traveled per unit of time. The average speed equals the total distance traveled over the total time traveled. One of the many real life examples that can demonstrate speed is a car. In this instance, I have chosen to use my dad’s Blazer. When traveling from my grandma’s house to my dad’s house it takes about 25 minutes (total time). My dad drives the car for about 20 mph for 20 minutes and about 50 mph for 5 minutes. To calculate the average speed, you would first find out the distance traveled at each speed. Then you would add them up to get the total distance traveled. From there you just divide the total time by the total distance.

Blog 4

This week, we have explored kinematics a bit more and have learned about more things than just speed. One of the things we have learned in class was about acceleration. Acceleration isn't only defined as the increase in speed, but can also be defined as the decrease in speed. Acceleration is the change in speed over time. For example, when pressing on the gas pedal of a car, you are accelerating (increasing acceleration). When pressing the brakes, you are decreasing in acceleration. I also learned that gravity has an acceleration of 9.8m/s^2, One of the ways I applied acceleration in real life other than driving a car is when I played Portuguese Horse Shoes. When I throw a ring, it starts of at it's maximum velocity but as time goes by, the drag of the wind, gravity and other factors decrease it's velocity causing it to arch and change direction. Once it changes direction and starts to move down, the gravity increases the ring's acceleration again (in the opposite direction).

Blog 3 - Kinematics

Kinematics can be defined as the motion of objects without reference to the forces that cause it. That being said, I have chosen to explain how Kinematics is present in paddling. Paddling involves a continuous, repetitive set of movements that involves mainly the arms, back and hips. As these movements are repeated from a stop, the canoe will accelerate until it has reached a constant speed. This can be calculated by putting velocity (how fast something is moving in a direction) over a period of time. If the canoe were going at a constant pace, the speed could be calculated by the equation v = d/t. For example, if the canoe traveled a distance of 20 meters in 2 seconds, you would find that the canoe was traveling at an average speed of 10m/s.

Blog 2

One thing that relates to physics is this tower fan. This fan works to produce wind. Depending on the mode (1, 2 or 3), it will produce a different amount of wind. These two variables are directly related. The higher the mode, the more wind it will produce. You could also say that the more wind it produces, then the better the circulation is in the room. In the case of comparing the mode and amount of wind, the mode is the independent variable and the wind is the dependent variable. When comparing the amount of wind and the circulation quality, then the circulation quality becomes dependent on the amount of wind.

Blog 1 - Intro

My name is Jezus Santos and I've been attending Kamehameha since 7th grade. I used to live in Nuuanu, but now I live in both Salt Lake and Ward. I remember taking Earth Science in 8th grade, BSCS Bio in 9th, and Chemistry in 10th. I find science a bit frustrating as I'm usually lost, but in the end I find myself getting through assignments/labs etc. I'm currently in Pre-Cal for math. I hope to obtain a greater knowledge on science, and hopefully science won't be such a hard subject for me anymore. It would also be nice to have a good grade. This picture of me was taken after me, my friends and uncles went diving at Chinaman's hat. I'm not that good, but I got lucky that day and caught some tako.This picture just represents how I enjoy the ocean and spending time with friends and family.