Physics Carol - On the 12 Days of Physics

On the first day of physics, Mrs. Gende gave to me:
a factor label method for converting units
On the second day of physics, Mrs. Gende gave to me:
one-dimensional kinematics
and a factor label method for converting units.
On the third day of physics, Mrs. Gende gave to me:
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the fourth day of physics Mrs. Gende gave to me:
distance and displacement,
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the fifth day of physics, Mrs. Gende gave to me:
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the sixth day of physics, Mrs. Gende gave to me:
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the seventh day of physics, Mrs. Gende gave to me:
SOH CAH TOA
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the eighth day of physics, Mrs. Gende gave to me:
vector components and addition,
SOH CAH TOA
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the ninth day of physics, Mrs. Gende gave to me:
projectile motion
vector components and addition
SOH CAH TOA
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the tenth day of physics, Mrs. Gende gave to me:
free body diagrams
projectile motion
vector components and addition
SOH CAH TOA
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the eleventh day of physics, Mrs. Gende gave to me:
Newton's three laws
free body diagrams
projectile motion
vector components and addition
SOH CAH TOA
acceleration due to gravity
acceleration
distance and displacement
constant velocity graphs
one-dimensional kinematics
and a factor label method for converting units
On the twelfth day of physics, Mrs. Gende gave to me:
OUR FINAL EXAMMMMMM!

Erika and Nicole's physics carol.

Newton's Laws of Motion

   Newton's laws have helped me understand the overall concepts of physics, and more specifically, motion, much better.  I have learned that:


Newton's 1st Law - Newton's first law states three basic ideas.
1.  An object that is not moving will not start to randomly move.  It stays at rest.
2.  If an object is moving, and there is not a constantly applied force, the object will continue to move at a constant speed.  However, if another force like friction is applied to the object, it will eventually slow down and come to a halt.  This is true in most cases.
3.  An object in motion will continue in the same direction unless acted upon by another force.  For example, if I am holding a rock in my hand and am moving my arm in big circles, whenever I decide to let go of the rock, it will continue to move in the direction that my arm and hand were last moving in.


Inertia is the resistance each object contains to not change it's state of motion at that moment in time.


I also now understand that the mass of an object is the same anywhere it goes, but the gravitational force (more commonly known as weight) can be different depending on where the object is in the universe.  For example, a 10 kg object is 10kg on earth, and on the moon, as well.  However, that same object will weigh 98 N on earth, but only 16 N on the moon.  This is because the gravitational pull on the earth is more than that on the moon.


I am now also very good at problems involving translational equilibrium, which is when the vector sum of forces upon one object add up to zero.  The object in translational equilibrium is not being moved in any direction because all of the forces cancel each other out.


Newton's 2nd Law - Newton's second law says that an object's acceleration is directly proportionate to the net force, and inversely proportional to the mass of that object.  For me, an example that helps me understand this law a lot better is if I am pushing a block across a horizontal table causing it to accelerate, and then proceed to push that block three times harder - the block will now accelerate three times faster.  The inversely proportional part of the law, using that same situation, means that if the block doubled in mass; the acceleration would consequently be half of the original acceleration.


Newton's 3rd Law - I have learned that Newton's third law basically means each action (or force) has an equal an opposite reaction.  For example, if I were to punch a wall: my fist would be exerting, for example, 800 N of applied force on the wall, and as a result, the wall would also be applying 800 N of force on my fist.  If we did not have this law, simple things like sitting down on a chair would be impossible.  The force of our body on the chair would not have a reaction force of the chair pushing up on our body, so we would simply fall through the chair.  


The last things I have learned are that apparent weight is the amount of force a body exerts on a surface it rests on, and mu helps find the amount of frictional force on an object, which is the opposing force of motion when an object is sliding, sitting still, or even rolling.


What I have found most difficult  in this unit is applying mu concepts to inclined planes.  On problem number 5 on homework 14, an object is sliding down a 30 degree angled ramp with no friction...I can not figure out how to find the mass, so in result I can't seem to find the acceleration, either.  I do not fully understand how to integrate vectors with aspects like friction on an object.  Also, I am sort of confused on what exactly mu is.  I don't really understand how it can have no units, and just be a number...What does the number represent?


I have studied mostly everything in this unit, but the concepts I have spent the most time on are pulley systems and how to approach problems involving a ramp (angle).  I have also spent a lot of time studying how to come up with equations and approach seemingly-difficult problems one step at a time.


My problem-solving skills have become much better due to studying this unit.  I think my ability to follow through each step of a difficult problem has gotten to the point where it comes way more naturally to me than it did before.  For example, I was working on homework #15, which talks about net forces and tensions, when I suddenly realized that everything I was doing, the steps I was taking, the equations, the relationships between the parts in the problem - everything was all very logical.    I think in the beginning of the year I struggled to understand the broad concepts and just focused on understanding the details; when now, I realize understanding what exactly you are doing and the general objective aids me much more than the small details when I go about solving a problem.  Still, I struggle most when first starting out an a problem.  It often takes me a while to think about what I am looking for, and make a plan in my head on how I will solve to get the final solution.


Overall, studying Newton's laws has been a very interesting unit and has greatly improved some of my key problem-solving skills.

Vectors and Projectile Motion

This is what I have learned about vectors and projectile motion:

  1.  Vectors are used to demonstrate the direction and magnitude of an object.  Say a ball is    being pulled in one direction at a certain magnitude, and the opposite direction at a different magnitude.  Which way will the ball actually go and at what speed?  Solving vectors answers this question.  

  2.  Projectile motion is when an object is launched without it's own motive power.  Projectiles always have a constant horizontal velocity, and a vertical velocity that changes throughout the time due to gravity.  An example of this would be a bullet fired from a gun at a 0 degree angle.  How far does the bullet travel?  Where exactly is the bullet at any given time?  What is it's final velocity?  Projectile motion equations aim to answer these questions.

  3.  Projectile motion at an angle is the same as projectile motion, but with an angle (theta) factored in.  A common occurrence of this is shooting a basketball.  Projectile motion is very helpful for solving everyday problems.  

What I have found difficult about what we studied is when I need to resolve the overall velocity into the separate x and y velocities.  But most of all, knowing where and when to apply the correct formula was the most frustrating to me.  There were so many that I couldn't keep track of them all at once.

My problem solving skills have GREATLY improved not only from studying vectors and projectile motion, but from physics class in general.  When I look back at my past work in the assignment and class notebooks, everything prior to these complex problems seems so simple.  Now, instead of focusing on the individual small parts of a problem, I try to look at the big picture first and see exactly what I need to do.  Although I feel much more confident when solving difficult problems, I still have a little trouble knowing where to start/what to do first.  However, I find that every time we start to learn a new concept, I think it will be so hard; but once I understand the overall goal of the unit, the steps start to come easier to me, and suddenly the problems from last unit that I thought were so hard now seem extremely easy.  

Projectile motion and vectors are definitely a part of every day life.  I bet that I see so many examples of these things everyday, but just don't realize it because they are so common.  For example, today at basketball practice I was shooting free throws - I seemed to keep on getting the right horizontal distance, but the vertical velocity being too small caused the ball to keep on hitting the front edge of the rim.  Thinking back, I automatically adjusted my vertical velocity by pushing upward on the basketball with more force than before without even realizing it.  This is a perfect example of projectile motion.

Vectors and projectile motion can be applied to many situations in everyday circumstances.

Verifying Velocity

Velocity can be a hard topic to explain.  What makes it different from speed or acceleration?  Velocity is a vector quantity that describes the rate and direction of motion in which an object changes position; unlike acceleration, which demonstrates the change in velocity of one object over a period of time.  Velocity takes direction into account (measuring only the total displacement) while speed determines the rate of travel using the total distance traveled.  Below is a Tagxedo summarizing the key words to understanding kinematics, along with a Pixton comic strip explaining more in depth the topic of velocity.  I hope this helps you better understand velocity and how it plays a very important role in physics!

How I plan to be Successful in Physics...

     I hope that this year I will not only be successful in physics grade-wise, but that I will also become interested in the subject.  In order to do well in this class, I believe I will have to work hard at the following five tips for success. 

1.  Come to class prepared and ready to work.  Being an active participant is essential if you want to get anything out of the class.   Part of being an active participant is taking notes, joining in on class discussions, asking questions, and pulling your weight in group activities. 

2.  Take advantage of all resources given.  In addition to reading the textbook, there are many online resources provided by Mrs. Gende that will be beneficial to my understanding of physics.  When reading information in the textbook, I plan on highlighting and annotating the text so it will be easier for me to study when I am preparing for finals.

3.  Stay on top of assignments.  Instead of doing homework the night before class, I will start it the night it gets assigned in case I have any questions.  After I finish the work, I will look over it to make sure I actually understand the concepts, to prepare for a future quiz.    The night before each class I’ll check the wiki to make sure I didn’t miss any assignments or things to study.

4.  Become a good problem solver.  Before starting to work on a problem, read over it again to make sure you know what the big picture is and what the answer is asking for.  After establishing what needs to be done, follow the four-step rule (write/sketch the data and units, create equation and solve for unknown, substitute values, check).  When it comes time to graph, make sure the graph is to-scale, neat, and labeled.

5.  Be an organized and self-sufficient student.  Keeping binders neat, seeking help whenever needed, and communicating with a group are all important parts of being successful as a student.  A prepared student is always ready to answer questions, or even take a test or quiz. 

     I believe that if I follow the five steps to being successful, I will have many opportunities to become a better student and become interested in physics.  I look forward to a challenging and interesting year taking Honors Physics!