In this unit I learned about...
In this unit, the main concepts that we covered included, inertia, newtons 1st law, equilibrium, net-force, speed, velocity, acceleration, and how to relate graphs and physics.
Inertia/Newtons First Law
Inertia lies mainly under the concept of Newtons 1st law. Inertia is demonstrated when objects in motion stay in motion, and objects at rest stay at rest unless acted upon by an outside force (Newtons first law). Ultimately, Newton's first law defines inertia. However, one of the most important things to remember while answering problems that use these two concepts in the answer, is that neither are nouns. You cannot say this object stayed because it had inertia. Inertia and Newtons first law are reasoning/laws explaining why things happen. Also, mass is a measure of inertia. Objects with more mass will have more inertia.
Example Problems...
When someone quickly removes a tablecloth out from under a set of dishes, why do these dishes stay at rest?
The objects stay at rest because the force exerted from pulling the table cloth out from under them was not enough to move the dishes in such a quick amount of time. Therefore, inertia was demonstrated because objects at rest will stay at rest unless acted upon by an outside force.
In a car, if you toss a coin up in the air, where will it land?
The coin will land directly back in your hand because it will stay in motion. While the car is still moving forward, the coin and other objects within are as well. We know this because of Newtons first law which states that objects in motion will stay in motion unless acted upon by an outside force.
In this picture, a man is falling off of his bike. (obviously). However, while his bike stops, his body continues to move. We know this because of Newtons first law which states that objects in motion will stay in motion unless acted upon by an outside force.
Net-force/ Equilibrium
Net-force is essentially all of the forces on an object. When something has a net-force, it means that it has acceleration and will be moving. Equilibrium is when something has a net-force of 0 newtons. Equilibrium occurs anytime a net-force adds up to 0 which includes when something is moving at a constant velocity, or when something is in rest.
What is force?
Force is a push or pull. It is measured in newtons.
1/4 Ib=1 N
Earth pulls down with 50N of gravity.
Example Problems...
A box is being pushed with 5N of force to the left, and 5N of force to the right. What is the net-force?
0 Newtons, the box is in a state of equilibrium.
A box is being pushed with a constant velocity with a force of 10 N. What is the force of friction between the floor and the box? How do you know this?
10 Newtons because when something is moving at a constant velocity it is in a state of equilibrium therefore will have a net-force of 0N. (no net-force). The force of friction must be equal to the force of the push.
NETFORCE=3N to the right.
Speed/Velocity
Speed and velocity are concepts that share multiple things in common. Speed and velocity are relatively the same, however, velocity requires direction. Therefore, if something is going at a constant speed it is also going at a constant velocity. However, if that object was to change directions while maintaining a constant rate, it would not have a constant velocity but would have a constant speed. If you change the direction, you change the velocity.
Formulas...
Speed=distance/time
you measure speed most commonly by meters/second
velocity=acceleration x time
constant velocity=distance/time
you also use meters/second for velocity
Example problems...
What is the velocity of a boat that went 100 meters in 50 seconds?
velocity=d/t
v=100/50
v=2 meters/second
This cheetah has a high velocity because it is running in one direction very fast.
here is our podcast on velocity.
Acceleration
Acceleration is a change in velocity. If something is accelerating it could be slowing down, speeding up, or changing directions. If something is in a constant velocity, it has no acceleration! If something is falling straight down, it will always have an acceleration of 10 meters per second squared.
formulas...
Acceleration=change in velocity/time interval
units=meters per second squared
distance=1/2 acceleration x time squared
example problems...
An object is going down a ramp very rapidly, increasing every second by 2 m/s. What is the acceleratin of the object after 10 seconds?
a=20m/s (squared)
If something is at a constant velocity, what is the acceleration?
no acceleration!
On new years eve in new york, the ball drops at midnight. What is the acceleration of that ball?
10 meters per second squared.
Equations of a Line
During our acceleration lab, we learned about how to convert our d=1/2at(squared) formula into an equation of a line.
Equation of a line...
y=mx+b
How do we convert the acceleration formula into this?
y=distance
m=slope
x=time
What I found most challenging:
As shown in my quiz grades, there were certainly aspects of this unit that I found challenging. I think that what I found most difficult was learning when to use different formulas. Because speed, velocity, and acceleration are all such similar concepts, there equations are as well. I often mixed these up on quizzes, leading to poor quiz scores.
HOWEVER:
"we learn from our mistakes" is a quote everyone knows. This definitely applies to my physics because I learned from what I did wrong in each question I answered. I also sought extra help from Mrs. Lawrence and friends to drill in formulas and meanings. I think what made this click is going over and over and over problems until I learn how to do them correctly.
Problem solving skills, effort, and learning
Problem solving skills:
One of my biggest issues in science/math is memorizing how to do something instead of actually learning how to do it. I think that this problem has occurred a little in physics so far, however the questions that Mrs. Lawrence give us challenge me to the extent that my previous approach does not always work. The problems that we face challenge us to search for and apply all the concepts we have been learning. I think that through this, my problem solving skills have definitely improved in all areas possible.
Effort:
I believe that in order to succeed in anything, effort needs to be presented consistently. In regards to homework, I think that I have put forth my best effort every night to complete the work, and understand it. I always try to engage in class and activities to further develop my understanding of concepts we learn. Also, I spend as much time as possible on my blog posts so that they makes sense, and help me and others reading them.
Learning:
There has been significant improvement of my understanding of physics as we approach the test. I think that I have learned how to apply concepts we are taught to real life scenarios through our podcasts, and class activities. Through effort, I think that I will certainly continue to learn and understand much more!
Overall...
Generally, I think that my self confidence as a student has increased. I feel more comfortable with the materials as we learn more and more about them. I collaborated very well with Jasira and Elise as we worked hard to complete a podcast on velocity. I look forward to growing more as a student in the next unit.
Goals:
I was not really aware of my dramatic grade drop until recently. My once 94 has transformed dramatically into a threatening 82 on the verge of a C and hanging on desperately to the B range. Not only am I dissapointed in myself, but I was caught off guard. Obviously, I was not paying enough attention to Physics to allow my grade to drop so much. Because of this, I intend to be a much more physics prioritized student next semester. I think that what hurt me the most were quiz grades which I hopefully will not do as poorly on. I hope that I can bring my grade back up and also understand future material that is given to me!
PART B: Connections
On the first day of physics class, Mrs. Lawrence told us that she would only teach us things relevant to our lives. Because of this, I believe that everything we have learned so far can apply to out daily lives. I now know why car accidents can often be fatal, how various concepts that include speed and force work, and can differentiate concepts that I initially thought were the same, from each other. What is so engaging in physics, is its consistent relevance to everything we do.
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