Unit 2 Blog Reflection

Newton's 2nd Law
Newton's second law stated that acceleration is directly proportional to force and inversely proportional to mass. In simpler terms, this basically means that as the acceleration goes up the force will increase as well and the mass will decrease however if the acceleration decreases the mass is increased. In formula form, it is written as a = F/M, where F is the force and M is the mass.
Another part of Newton's Second Law was the fact that mass and weight are not equal. In order to find the mass of and object you simply divide the weight by 9.8 (rounded to 10) or to find the weight of something you multiply the mass by 9.8 (rounded to 10). A simple formula to remember for this process is W=GM. Where the W is representing your weight, the G which stands for gravity is the 9.8 (rounded to 10) you multiply or divide with, and the M is your mass.

Sky Diving
In  our sky diving lesson, we learned immediately that the speed that an object travels in the air effects your air resistance in a manner that is very similar. In fact a persons speed and air resistance are directly proportional to one another. This will happen until the object that is in the air reaches a terminal velocity (constant speed). In this picture, we see a picture of a man sky diving. In the (a) step, we see he is jumping out of the plane from rest so his force is only 980N, which looks sort of like 9.8 (force of gravity). As he is falling he begins to accelerate because as we stated earlier in Newton's Second Law, force is directly proportional to acceleration. In step (c), he is still increasing acceleration and his velocity and acceleration are all going downward. However, in the (d) step, when he opens up his parachute, his velocity is still going downward, but his acceleration is now going upward. Don't let this confuse you though. All this means is that he is beginning to slow down. He is going to continue to slow down until he slowly reaches terminal velocity again. With more air resistance now hitting the man due to the parachute, his speed steadily drops.



Free Falling
In free fall, their is absolutely no air resistance, there for gravity is the only force action on any falling object. Knowing this, we know that the weight of an object no longer matters, because gravity is the only force pushing on the object which gives us 9.8 (rounded to 10). So if you were to drop two things from an equal height in free fall, whether a feather and a coin or two balls of different mass, they will hit the ground at the same time.

Throwing Things Up

This is a video that my group made about throwing things up in the air. Just remember this is how you would typically solve for one of these problems.









Projectile Motion
In projectile motion, there are two terms you need to know:

• Vertical Distance: has a constant acceleration (10m/s^2). We use the formula d=1/2gt^2. Vertical velocity is basically the height, and the height determines time.

• Horizontal Distance: always remains with a constant velocity because it has no force. We can calculate horizontal velocity by using the formula v=d/t

My Problem Solving Skills and etc...
This was a tougher unit for me because it was alot of things you had to know to fully understand Newton's first law. Saying this, I tended to get frustrated alot, even in group project I started to shut down when I didn't understand a problem, however now i understand it due to the several labs that we did in this unit. The videos that I watched on my own also helped me alot. My goal for next time is to never give up, even when the work load seems to get intense, I have to continue to work at it and ask several questions.

Free Fall

In this video it describes what free fall is and like in all my other videos, I chose this video in order to relate it back to things we do in every day life. Not that we go to the fair everyday but we have seen or either rode this ride before. He does a great job explaining how this ride is under free fall. 

Newton's Second Law

I chose this video because it describes Newton's Second Law in a way that alot of people who love sports can understand it by relating it back the very sports we play. In this example, football. It deepened my understanding on what Newton's 2nd Law was.

Unit 1 Blog

Newton's 1st Law

In this first blog, we talked alot about Newton's First Law (which is an object moving or at rest will remain moving or at rest unless acted on by an outside force). In talking about this we opened up by first doing a project entitled the Hovercraft. In this project, we pushed a hovercraft that had 0N of friction to the ground and watched as it moved forward with a constant velocity. This followed Newton's 1st Law because when at rest it would not go anywhere but once we added force to the hovercraft, it continued to move forward without any variation of its speed. When Sean Wrinkle stopped the hovercraft, he was acting as the outside force to this whole law. So he caused it to go in a different direction. 

 

Acceleration vs. Velocity

 In talking about the speed of something however, we can't go on further without explaining the difference between acceleration and velocity. Acceleration is defined as the rate of change of velocity over the amount of time it took to change (written as a = Change in V/T). While velocity is the rate of speed in which something happens (written as v = D/T). An object can have a constant acceleration, and that is when it steadily increases its acceleration by the same number each second or so.

 Acceleration in this picture would be if this truck continually accelerated each second by 2 m/s^2. If something had been going through a constant velocity it wouldn't be speeding up nor slowing down. It would stay at the same speed meaning it is an equilibrium. The formula for constant acceleration is d=1/2 at^2 while the formula for constant velocity is V= d/t.

Equilibrium and Inertia

An equilibrium is a state of rest or balance due to the equal action of opposing forces. So a car at rest, or an object that is traveling with a constant velocity would be an equilibrium. Inertia, is the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by an external force. An example of this is if a boulder was rolling down a hill and you wanted to stop it, you would struggle and because it wants to remain rolling.

 Formulas:

v = at (acceleration)
a = Δv/t (acceleration)
d = 1/2 at2 (distance = 1/2 acceleration squared)
v = d/t (constant velocity)

y = mx + b (slope of a line)

Difficulties As Well As Goals:

So far in physics class, I have struggled with fully understanding the concept of acceleration. I seem to struggle with the fact that if an object goes around a curb with a constant speed it is accelerating. In the beginning I seemed to struggle because we learned earlier that if something is at a constant velocity, it has an acceleration of 0m/s^2. It wasn't this concept I struggled with however, it was understanding that speed doesn't directly mean velocity. I feel that I need to improve my study habits and turning things in on time in order to increase my grade and understanding of things in class. This would be one of my goals for the class, improving the way I study and turning my assignments in on time for the remainder of the year.

My Lab Video:

Constant Velocity vs. Constant Acceleration

The purpose of this lab was to introduce us to the ideas of having a constant velocity versus having a constant acceleration. From this lab, I learned that having a constant velocity is having a speed that does not change how fast it is or the direction that it is going. However, having a constant acceleration means the object is accelerating at a constant rate but tends to get faster depending on the slope its on.I did both of these tasks by using simply a marble and a piece of chalk. To test out constant velocity, I rolled the marble on a flat surface and at every half second, I would mark where it was using the chalk. 

This is an example of what the graph looked like from my results of marking where the marble was at every half second. To measure a constant acceleration, we did something alot similar to the first experiment, but instead of having a flat surface, we made an incline and let it roll like normal. This graph looked something like this:

The formula for constant acceleration is d=1/2 at^2 while the formula for constant velocity is V= d/t.

From this lab, I learned the difference between constant acceleration and constant velocity, I learned that whenever I see a straight lined graph it is because the object in motion has a constant velocity and whenever I see a curved line it is because the object has a constant acceleration. 

Inertia

In this video, it shows an example of how inertia works in a car. Knowing Newton's 1st law, an object in motion/rest stays in motion/rest unless acted on by an outside force. In this example we see the car and you are in motion, and once the driver presses on the breaks you continue to want to go forward because you were already in motion. Inertia is the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by and external force (dictionary.com).

Acceleration and Velocity

This is a video of the 2008 Olympic 100 meters finals in Beijing. This race shows acceleration because starting out of the blocks a runner must speed up by changing his velocity. If you noticed in Usain Bolt's last 20 meters when he knew he was going to win he stopped accelerating and driving, but he was still going the same speed. How is this possible? Usain Bolt decreased his acceleration yet his velocity stayed constant, thus allowing him to when the 100 meters .2 seconds before everyone else.

The Hovercraft

In physics class, we were given the opportunity to ride a hovercraft to get a feel for an object in motion that has no force pulling it. Riding a hovercraft was a unique experience. Before riding one I had no idea what to expect. It was weird because I'm so used to riding in a car or on other things that typical slow down to stop, however this did not. It kept moving at a constant speed until hit by an outside force. From this lab i learned that an equilibrium has 0N and this is seen if the object is moving at a constant speed or is staying still. A net force is the force that pushes an object that is measured in newtons (N). Based off the lab, on can hypothesize that acceleration all depends on the first phase. Based off the lab, you would expect to see the hovercraft having a constant velocity in the second phase when there is no push or pull on it. Some of the people riding the hovercraft however, went faster than others. This was because the bigger people were harder to push than the smaller people therefore I didn't have to exert much force.

Why Physics

In chemistry this year, I hope to learn how a bowling ball in a bowling alley tends to either speed up or stay the same speed, but never seems to slow down, how the longer a long jumper stays in the air affect his or her jumping distance, and lastly all three of Newton's laws. Physics is a very important thing to study during your high-school careers because alot of the things we talk about in physics will relate to our everyday life, it open our eyes up to view things in a new perspective, and it is just a fun topic/section in high school that shouldn't go unstudied. Although physics seems to be the well liked science course at the Asheville School, there are still questions that seemed to have gone unanswered like who started the study of chemistry, what do chemist on college do, and after college what job opportunities are there for chemist? This year in chemistry class, I hope to grasp the full definition of chemistry, learn the differences in the Newton laws, and have fun.