Is my book right? it seems wrong

[Tim.thelion]

I don't get this it seems that the reemition would not always be 180 deg from the cachpoint...
http://mysite.verizon.net/res8szeo/homework%20012.jpg
http://mysite.verizon.net/res8szeo/homework%20013.jpg
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[Chi Meson]

In this chapter, Paul Hewitt is "mostly right" in that the more complicated explanation is left out. You will need to get to quantum physics (about 3rd year of college) to get the full explanation here. The fact that the re-emission is 180 degrees from the absorption is the reason why glass is transparant as opposed to transluscent.

According to quantum mechanics, materials may absorb or re-emit a photon; if the photon re-emits, it may be reflected, transmitted or scattered. Quite complicated. ZapperZ is the guy you want for deeper explanation.

By the way, Hewitt is about the best author for physics at this level. His only errors are those of omission, and then only arguably (since eavery author has to decide where to stop giving information).

 

[dicerandom]

You will need to get to quantum physics (about 3rd year of college) to get the full explanation here.

I was about to say "we didn't do that in my 3rd year quantum class," but then I remembered all those dang step potential problems. Never occurred to me that's what we were doing at the time though ;)

 

[Tim.thelion]

I gues that makes sense. I'm in 9th grade so it'll be awhile.
Qoute:
By the way, Hewitt is about the best author for physics at this level. His only errors are those of omission, and then only arguably (since eavery author has to decide where to stop giving information).

that is weird because in at least my 7th edition book he does things like describes cd's in the section on sound which is just dumb, I think.

 

[Chi Meson]

that is weird because in at least my 7th edition book he does things like describes cd's in the section on sound which is just dumb, I think.

Pardon me, but I am irked.

So a ninth grader is deciding when a 40-year veteran physics professor, a recipient of the Millikan Award from the American Association of Physics Teachers, a man who revolutionized the way Physics is taught, one of the finest teachers of the subject in this country...is being dumb.

I think you should read the text from the point of view that:
if you don't understand why, assume it's because you didn't get it the first time: time to read it again. Stop assuming it "must be because the author is dumb" or "the book is pooly written."

As you read it again, you will see that Hewitt informs you that what we know of light and how light behaves allows us to have CDs. What we know of magnetism allows us to use magnetic tapes. Why do you NOT want to know about them? That's what seems dumb to me. Physics is not just a bunch of facts to memorize. All this stuff is useful.

 

[Tim.thelion]

I understand almost everything in the book on first reading. I was getting annoyed because of oversimplifications and poorly placed sections. If the part on cd's had been in the light section that would make sense to me but it was in the sound section. I could write a rather long paper on the things that are wrong with the book and why if you want me to. I just felt that there was a lot of potential confusion in the placement of some of his sections. I in-fact have been reading an entire section before even beginning the problems.

Ps. I would be reading Giancoli but I am only at Saxon Algebra 2 this year in math and his book is littered with trig (you don’t think I’m behind in math do you?)

 

[Chi Meson]

9th grade in algebra 2? No you're not behind in math.

And if you wrote a lengthy paper, it would be on your opinion of why you don't like the book. Opinions are fine. It won't change the fact that Hewitt's work is still one of the finest textbooks for "first-time" physics students. You won't find anyone textbook that satisfies all need. Go ahead and read Giancoli as well; the combination has proven to be very successful ("get your feet wet, then go deep")

But as you read the rest of Hewitt, remember: the guy does indeed know what he's talking about.

 

[Tim.thelion]

I guess I should stop listening to my dad ... he was the person that suggested it was wrong;) well anyway I will not doubt any longer I have an evil habit of becoming distrusting with disagreements I hear Tesla was the same way;) wouldn't mind being a little like him

 

[Tuneman]

I understand almost everything in the book on first reading. I was getting annoyed because of oversimplifications and poorly placed sections. If the part on cd's had been in the light section that would make sense to me but it was in the sound section. I could write a rather long paper on the things that are wrong with the book and why if you want me to. I just felt that there was a lot of potential confusion in the placement of some of his sections. I in-fact have been reading an entire section before even beginning the problems.

Ps. I would be reading Giancoli but I am only at Saxon Algebra 2 this year in math and his book is littered with trig (you don’t think I’m behind in math do you?)

If you are in algebra 2, you must really can't complain about the simplified versions of things, because if instead of giving his explinations of light, he instead told you how to find the transmission and reflection coeffients of the coresponding wavefunctions, you would be complaining about how tough it was.

Edit: I am not sure what kind of school you are in, however I strongly disagree with physics being taught in a 9th grade cirriculum, it should be a 12th or at the earliest 11th grade course.

 

[Chi Meson]

Edit: I am not sure what kind of school you are in, however I strongly disagree with physics being taught in a 9th grade cirriculum, it should be a 12th or at the earliest 11th grade course.

Hewitt's "Conceptual Physics" text can indeed be taught to high school freshmen. There is no math beyond basic algebra 1 required. Not all 9th graders are ready for it, but the good students among them can benefit from understanding the principles of physics first, and then applying them to what they subsequently learn in Bio and Chem. WHen they return to physics as a senior, then the problem-solving can kick in.

You might have guessed, I am a huge fan of Paul Hewitt.

 

[Chi Meson]

I hear Tesla was the same way;) wouldn't mind being a little like him

We do need more Teslas.

 

[Tuneman]

Hewitt's "Conceptual Physics" text can indeed be taught to high school freshmen. There is no math beyond basic algebra 1 required. Not all 9th graders are ready for it, but the good students among them can benefit from understanding the principles of physics first, and then applying them to what they subsequently learn in Bio and Chem. WHen they return to physics as a senior, then the problem-solving can kick in.
You might have guessed, I am a huge fan of Paul Hewitt.

You are not going to apply much high school physics to high school biology or chemistry, I can tell you that right now. Also, the "problem-solving" skills you are going to be getting from reading a physics book requiring only algebra I will be far outwieghed by the benefits of other classes you can take, I assure you that. When you get in a real physics class for the first time, and the teacher starts deriving the equations of position, velocity, and acceleration (along with other concepts covered) the algebra I physics class will be moot.

 

[Tim.thelion]

I go here http://www.chrysalis-school.com/Program.htm I have been designing my own curriculum and do what I want to do. I am legally illiterate (I can't write with pen and paper because of simple symbol analysis problems, no one has really explained that part to me I just know If I write more than a sentence My hand starts to hurt) This is why I worry about being behind in math... I am a computer programmer (taught myself (with dads help) at the age of 9) I am bellow grade level in English. Basically I just want a good education and new I couldn't get one in special ed. My mom say's I should do bio next.

 

[Tim.thelion]

My schedule... as you see my school is not "normal" .. no classmates just me and my teachers. I learn what I tell them to teach me.
http://mysite.verizon.net/res8szeo/homework.jpg

 

[Seiya]

the first thing that comes to mind is that you shouldn't treat your book that bad it looks so old and wrongly treated :(

:P

 

[Tim.thelion]

It was like that when It came to me