Why am I not doing well in physics?

[fastrunner101]

I'm taking AP Physics C Mechanics in school. And I have spent the most time studying for physics than any of my other classes or extracurriculars. I study by doing reading the book, working out sample problems, doing homework problems my teacher assigns us, the concept questions at the end, watching additional videos for each chapter. I take twice as long to finish a problem set than my counterparts, and this has been the case for every single chapter thus far. I might have understood everything they were explaining in chapter while reading, but when the questions come, I write down my unknown variables, the formulas that I might use, and when I don't get the right answer I can't always figure it out on my own. Did I really understand it? If so, why couldn't I get the right answer. If not, why not?

There's a sort of innate thinking that the students around me have that allows them to grasp things quickly and do things effortlessly. How can I also think like them?

I'm wondering if I'm reading the book the right way. I used to take like heavy notes on each chapter, but then I realized that was not really helping and began to make flashcards out of each formula I found during the process of reading the book. How do I know if I truly understood? I would only find out during our concept quizzes. Sometimes I would get an A, other times its a C. I've never done mediocre in any test/quiz thus far in physics, it's on either extreme. Are the questions really helping me? What should be my approach when I am STUMPED on a question? Should I skip it then return? My friends are too busy with their own work to help or study with me and I still go to visit my teacher during lunch as much as I can to reflect on my quizzes and ask questions, but it's not enough to excel or even get on track. I'm defeated, and exhausted.

I aimed to get a quarter A, but managed only a low B this quarter, having done all of these things when studying. What is even worse is that we are covering about a chapter each week, so the pace is very fast. I am not going to drop out, but I need to know how I can work towards an A. I'm very helpless. What I fear even more is the semester test in which ALL chapters learned thus far are going to be on it. How will I have time to review my previous chapters when I can't even manage a single chapter. I want to incorporate spaced repetition, but I don't see how I can practically manage everything.

I have a concept quiz on rotational motion tomorrow and I don't want to start my quarter off with a C. Please suggest some efficient ways to understand the concepts and study in an effective manner.Physics truly fascinates me, and I want to be really good at it.

 

[berkeman]

I have a concept quiz on rotational motion tomorrow and I don't want to start my quarter off with a C. Please suggest some efficient ways to understand the concepts and study in an effective manner.

Can you show us a typical exercise problem that you have solved in studying for this test? And also, can you show us a very challenging problem for this class that you have not been able to solve yet? That will help us to understand where you are currently, and offer some ideas. You can upload images of the problems using the "Attach files" link below the Edit window...

 

[Vanadium 50]

I have a concept quiz on rotational motion tomorrow and I don't want to start my quarter off with a C. Please suggest some efficient ways to understand the concepts and study in an effective manner.

...by tomorrow.

One thing that will help is not waiting until the last minute.

 

[symbolipoint]

...by tomorrow.

One thing that will help is not waiting until the last minute.

In fact, two things to be done in a difficult course are these:
(1) Study the topic before it is instructed in classtime;
(2) Study and review the topic as promptly after the classtime presentation of the topic as possible.

Later in the day(or night) you review again, and do sample or example exercises, and your homework exercises.

 

[Hall]

As far as my experience is concerned, Physics problems upto the first year of College are not solved, they are recognised.

Don't get into fallacy: "If you cannot solve problems then you have not understood it".

 

[CrysPhys]

As far as my experience is concerned, Physics problems upto the first year of College are not solved, they are recognised.

Don't get into fallacy: "If you cannot solve problems then you have not understood it".

I haven't a clue what this means. Care to elaborate?

 

[Hall]

I haven't a clue what this means. Care to elaborate?

Which part, sir?

 

[CrysPhys]

Which part, sir?

All of it.

 

[gleem]

How do I know if I truly understood? I would only find out during our concept quizzes. Sometimes I would get an A, other times its a C. I've never done mediocre in any test/quiz thus far in physics, it's on either extreme.

A C is mediocre, isn't it?

I'm not sure what a concept quiz is but I will assume if you do not know the concepts then you will have difficulty applying them. You should know that problem-solving is not just finding the right equation, but a process of decerning relationships ultimately revealing the solution.

As @berkeman suggested showing us a problem that you did and one that you had difficulty with would possibly help us recognize deficiencies in your approach.

Presumably, you finished your concept quiz on rotational motion, how did you do? Did you have any problems, if so what were they?

 

[Hall]

All of it.

I'm a very Pangaloss-type of man to expect that my post (containing more than 500 words) will be read.
It is didactical to begin with an example, though it is about the concept and not the concept itself. In the first course of Differential Equations we are taught to solve
$$
y' + P(x) y = Q(x)
$$
And we solve it thus,
$$
\begin{align*}
\textrm{ we try to make LHS to be a derivative, because it looks like a derivative of a product}\\
uy' + uP(x)y = uQ(x)\\
\textrm{ If we now assume that LHS is the derivative of (uy) then we must have}
u' = u P \implies u = e^{\int P dx} \\
y = \frac{1}{e^{\int P} } \left(\int u Q(x) dx+C \right)\\
\end{align*}
$$
If we understand that clearly, we get an idea of it. So, if we are presented with something like
$$
y' + xy = \sin x
$$
We would recognize it ,and just as our brain learnt from the first burn from fire that all things of that form cause that pain and any healthy brain would recognise it if it were to come before it again, and simply solve it by replacing P and Q with the corresponding functions.

We wouldn't solve the exercises on linear first order ordinary differential equations after studying the above, we would recognise and compute the textbook problems. We won't solve, it was solved by Leibniz, the currents in our brain goes through the same path, only at a few junctions some passengers get out and new ones come in.

So, in problems of Mechanics, upto the said level, we try recognise the problems so as to drop our previously conceived psychological object onto that problem. For example, the whole of dynamics is pivoted around Conservation of Momentum, the students are merely trained to see it in given problems.

On the hand, in Analysis we do not recognise and compute that often (I think in Analysis almost every problem is a theorem). If we reflect on what processes are actually going on inside our brain when we try to prove Intermediate Value Theorem geometrically, we would find that though we have seen a continuous curve so many times yet we never cognised that it takes all intermediate values. We simply conclude that "it cannot happen otherwise, it cannot reach a higher point without traversing in-between points", we cognise it upon our first confrontation with IVT.

Solving an indefinite integral in first course of Calculus is just about recognition.

I must accept by now that gentlemen reading my post are of high intellectual level and therefore, they might have got an idea of what I'm trying to put forth.

The second part doesn't need very much of amplification. Again I will take the help of an example; Suppose, a student is asked to find the work done in moving an object from ##x= 1## to ##x= 1.5## if force at every point ##x## is given by
$$
\frac{
(\sin^n x -\sin x)^{1/n} \cos x }
{ \sin^{n+1} x }
$$
the student must be knowing the physics, but does failure in computing the work done imply that the concept of work is not well understood?

Sometimes some Physics problems are so described as the reader doesn't get a faintest idea of what is happening.

There are few topics in Physics which involve almost no concept but only through problems we get to know the concept, the most conspicuous ones that I can think of are: Buoyancy and Electric circuits.

That's all I had in my mind.

 

[CrysPhys]

I'd like to buy a vowel. I'm a Cro-Magnon-type of man.

 

[fastrunner101]

Can you show us a typical exercise problem that you have solved in studying for this test? And also, can you show us a very challenging problem for this class that you have not been able to solve yet? That will help us to understand where you are currently, and offer some ideas. You can upload images of the problems using the "Attach files" link below the Edit window...

Before going into the test, I had done spent a good amount of time on these 10 concept questions at the back of the book in addition. Among these I had been able to solve 7/10 before going into the test. Here are 2/7 I solved:

My work for those questions:

A question similar to one of the questions I hadn't been able to understand and was challenging for me (despite searching it up and asking for a friends help) had been this one (I drew the reference line from point p and then made the perpendicular line from the force to that reference line, but couldn't make sense of the angle):

I did have the opportunity however to talk with my teacher about some of those concept questions (including this one) and I'm clear with them now. We only started the chapter on Friday and we had a 3 day weekend so that prevented me from consulting with my teacher earlier.

I think I know now that I have this platform to reach out for any questions I need help with, I just need to figure out how to manage my time to be ahead so I can ask questions well before the test.

 

[fastrunner101]

...by tomorrow.

One thing that will help is not waiting until the last minute.

Yes that is true! I have learned not to start studying last minute- and that's why I started studying on Friday when my teacher introduced the chapter to us. I had 3 days to study for this conceptual quiz, which wasn't really supposed to be hard at all (according to him). And that's exactly what I did. I spent as much time as I could trying to understand the textbook of this chapter, finishing up questions from the previous chapter, and then attempting the concept questions.

 

[fastrunner101]

In fact, two things to be done in a difficult course are these:
(1) Study the topic before it is instructed in classtime;
(2) Study and review the topic as promptly after the classtime presentation of the topic as possible.

Later in the day(or night) you review again, and do sample or example exercises, and your homework exercises.

Yes, I suppose it's a good idea to set aside time to read the chapter prior to class. Usually I'm still struggling with the previous chapter, that I don't want to start the next chapter until I get more of a grasp on it. I guess I just have to work on my mindset.

 

[fastrunner101]

A C is mediocre, isn't it?

I'm not sure what a concept quiz is but I will assume if you do not know the concepts then you will have difficulty applying them. You should know that problem-solving is not just finding the right equation, but a process of decerning relationships ultimately revealing the solution.

As @berkeman suggested showing us a problem that you did and one that you had difficulty with would possibly help us recognize deficiencies in your approach.

Presumably, you finished your concept quiz on rotational motion, how did you do? Did you have any problems, if so what were they?

Yes I believe I did pretty average on the quiz- basically a concept quiz isn't numbers heavy and asks questions similar to concept question questions I replied to @berkeman with and also simple mathematical calculations (like calculate the rotational inertia over an axis, convert velocity from rev to radians, or two points on a circle compare the angular/linear velocities and accelerations and that was easy for me I'm confident got that)

I had like, a lot of confusions with concepts overall during the test. I realized after discussing with my classmates, I think I got some questions right by fluke.

One of the questions was like a bicycle is going eastward so which direction was the velocity going and I initially thought, hmm the motion of wheel of the bicycle is rotating clockwise, so maybe the velocity is going westward? But then I thought if I use the right hand rule and curl my fingers towards east the vector points northward... so it's north? I put north as my answer.

And then I also messed up on the question similar to question 8 I replied with above where there were 3 forces that pushed on an object and it asked if the direction of the motion was clockwise or counterclockwsie.

There was another question where it said an object travels Θ in time t, how much does it travel in t/2? But I don't quite remember right now if any information was given regarding the acceleration? And I think I was supposed to use the ΔΘ = ω0t + 1/2αt^2, I assumed ω0 was 0 and acceleration was 1... and then the answer was Θ^2/4? (I will review this question and reflect here)

And I have to be honest, I felt really dumb not being sure about this and I hope I didn't get it wrong, but it showed this fan rotating in a clockwise direction slowing down and it asked for the signs of angular acceleration and angular velocity and I think of course because it was decelerating the acceleration was negative and if acceleration is negative and it is the derivative of velocity, I could also assume... velocity was negative right? Or... see this is where I got kind of confused because when something decelerates the velocity decreases but the velocity was positive in this case when decelerating. But because the motion was cw, the velocity should've also been negative? I answered that that both acceleration and velocity were negative.

I will get my score soon, and probably see my teacher during lunch to go over the quiz. I will reflect here once that happens.

Perhaps because I've generally worked equally as hard to get A's in other classes I find it hard to digest a mediocre C, and thus it is an extreme for me.

 

[hutchphd]

It is very difficult to know your particular difficulties without interacting closely with you as a teacher, so I will assume that you are fully capable of doing well. and proceed on that basis

Physics is process. It is a coherent set of rules by which we have agreed to seek out, and then qualify useful answers from, the surrounding universe. Beginning physics consists of simple examples of these techniques. Bright students are often difficult to teach because often they can do the simple problems without learning the techniques, but the point is to learn the techniques. The technique is not to shake the big box of equations, pull one out, and see if it fits. The technique is not to keep track of the signs of acceleration in your head: draw a diagram and define your coordinates. The techniques are there to allow you a chance to solve the really hard problems that no one can intuit.

In terms of studying the best time you can spend is to read enough ahead that you can walk into the lecture knowing that if a friend says "Hey what is this class lecture about?" you can talk for 1 minute about it. Then you will have understood what you need to learn that day, and always ask about the difficult stuff. Spending more time is not always the answer but spending more quality time usually is. And never get behind.

 

[symbolipoint]

Yes, I suppose it's a good idea to set aside time to read the chapter prior to class. Usually I'm still struggling with the previous chapter, that I don't want to start the next chapter until I get more of a grasp on it. I guess I just have to work on my mindset.

Referring to my points (1) and (2) regarding the quote here --
For you, both those points are more than just good ideas. You still struggle with "the previous chapter", and your only way to avoid always being in the position is STUDY AHEAD.

@hutchphd had some good ways to talk about this/these/that too.edit: earlier mispelled hutchphd's username.