So I'm studying and need help...

Serendipity

Been studying for Physics all day today, and came across an old test question that I could not solve:

"A cyclotron is designed to accelerate deuterium nuclei. (Deuterium has one proton and one neutron in its nucleus). (a) If the cyclotron uses a 2.0-T magnetic field, at what frequency should the dee voltage be alternated? (b) If the vacuum chamber has a diameter of 0.90m, what is the maximum kinetic energy of the deuterons? (c) If the magnitude of the potential difference between the dees is 1500V, how many orbits do the deuterons complete before achieving the energy of Part (b)?"

I've been stumped for a few hours now (will try to post a scan of my work) and I'm not sure where to go with the problem. I'd like to try and work out the problem myself, so I'd rather know how it was done than just have the answer. Where should I start? I tried using Force = q(E+V*B) but I'm not sure if this is right???

Thanks!!

P.S. Please tell me all this studying is worth it!!

dragon1952

appadv wrote: »

Been studying for Physics all day today, and came across an old test question that I could not solve:

I've been stumped for a few hours now (will try to post a scan of my work) and I'm not sure where to go with the problem.

I'd go to the reefer with it and grab a cold one

dragon1952

appadv wrote: »

P.S. Please tell me all this studying is worth it!!

yes, and it definitely beats some of the alternatives like drinking and chasing women Hmmm...on second thought :cool:

tcrossma

I think the studying is worth it, so keep it up! I personally don't understand a word of that problem, and I myself didn't pay enough attention and drank too much back in school to have any hope of ever answering such a question. But i'll tell you what, I'm sure hoping my son takes a more serious approach to schooling than I did. I deeply respect those that can make it through today's institutions without taking the easy path and goofing off through the whole thing.

Good luck!

BaggedLancer

I just finished doing a report that took me just over 7 hours today to do. Now, it's time to eat dinner and throw back a few cold ones alcholic style....still in the paper bag.

Enjoy your saturday night studying!

Bamadude

I really don't remember studying anything about particle acceleration in the physics classes I took, but I did find some stuff on wikipedia that might help. Go here and scroll down to the Mathematics section. The next to last formula for frequency with B*q/2*m*Pi looks like it might be relevant since you already know B-magnetic field, q-charge of the deuterium particle and it's mass-m. Good luck.

Serendipity

tcrossma wrote: »

I think the studying is worth it, so keep it up! I personally don't understand a word of that problem, and I myself didn't pay enough attention and drank too much back in school to have any hope of ever answering such a question. But i'll tell you what, I'm sure hoping my son takes a more serious approach to schooling than I did. I deeply respect those that can make it through today's institutions without taking the easy path and goofing off through the whole thing.

Good luck!

Thanks, I'm trying my best to do well on these upper-level Physics courses and then hopefully go on to grad school (see other thread). But my eyes are getting really tired and I can't see well, so I'm going to sleep soon.

On the other hand, I'm still working on the problem right now and threw away 3 pieces of paper because I got stuck each time...

nms

Don't anyone take this the wrong way, but this is probably not the best place to ask for physics advice on a Saturday night!

I was doing solids tonight, (mechanical engineer), 1.5 hrs on 1 problem. I feel your pain man.

Serendipity

nms wrote: »

Don't anyone take this the wrong way, but this is probably not the best place to ask for physics advice on a Saturday night!

I was doing solids tonight, (mechanical engineer), 1.5 hrs on 1 problem. I feel your pain man.

What school do you go to? I almost ended up in NC when I got waitlisted to Duke, but unfortunately that never worked out...

Would be fun though, there's a lot of NC Polkies on this board...

CAvolleyballguy

appadv wrote: »

P.S. Please tell me all this studying is worth it!!

Well I never studied anything like that in Physics or Pchem, or I did and I have since forgotten seeing as how I once got a 35 on a test AFTER the bell curve was applied to a high score of 59. That means my original score was a frikin negative number... Is it possible that, that professor just sucked.

to answer your question, no, it is not worth it. Here are the types of multiple choice type questions you will find along your career.

A. They have computers to figure that out.
B. Learning the Theory and having computers figure out the answers makes more sense and should be how classes like this are taught.
C. unless you go to work at a particle accelerator you will never use this information ever again, and even if you did, the computer would figure it out for you.
D. All of the above

Serendipity

I guess my professor is just one of those hard graders. I have a few friends that took his class before and ended up having to take it again due to the harsh curve.

nms

appadv wrote: »

What school do you go to? I almost ended up in NC when I got waitlisted to Duke, but unfortunately that never worked out...

Would be fun though, there's a lot of NC Polkies on this board...

NCSU.

BaggedLancer

I would just give up now appadv.

Serendipity

BaggedLancer wrote: »

I would just give up now appadv.

I haven't given up yet!

If you don't mind telling...what's your major, BL?

petrym

CAvolleyballguy wrote: »

A. They have computers to figure that out.
B. Learning the Theory and having computers figure out the answers makes more sense and should be how classes like this are taught.
C. unless you go to work at a particle accelerator you will never use this information ever again, and even if you did, the computer would figure it out for you.
D. All of the above

You're completely missing the point of the class, professors are teaching you to think and how set up the solution, the answer is not what they are trying to teach.

Serendipity

petrym wrote: »

You're completely missing the point of the class, professors are teaching you to think and how set up the solution, the answer is not what they are trying to teach.

I'm sure there are computers that can do the problem in a flash, but the point is to be able to set up and solve the problem, not just get an answer

treitz3

.......and to be able to verify thru process that the computer is correct. Not that the computer would be wrong, mind you, but humans are wrong and one slip of the keyboard could cause a major catastrophic failure when and if the design makes it past a certain point.

If you do not understand the theory, you understand nothing.

BaggedLancer

appadv wrote: »

I haven't given up yet!

If you don't mind telling...what's your major, BL?

It's highly classified. So classified I keep it in my AIM profile. Sorry.

CAvolleyballguy

petrym wrote: »

You're completely missing the point of the class, professors are teaching you to think and how set up the solution, the answer is not what they are trying to teach.

perhaps you "completely missed the point of my reply"

I did say... there are better ways to teach... To learn the theory... not make people do drone busy work... 2hrs on a single question..is a ridiculous amount of time to waste...the fault is on your professor, if they are anything like my school, and I went to a good one, 99% of them were worthless, 2 on the entire campus were worth a damn. problems that difficult should be worked on in class where a professor can step in and guide you.

There are also much better ways to learn critical thinking skills. Doing difficult mathematics is hardly one of them.

Look.. You're the one that asked..and I gave you an honest answer. I've been there... reading the same f'ing paragraph over and over again trying to figure out how to even set up the chemical reaction, all the time knowing, i could plug it into a model and have an answer in 10 seconds..

I truly feel I blew 100K on a worthless education. I have a B.s. in biochemistry, I graduated from a prestigious private college and i can tell you those classes were a waste of my time.

Unless you plan to have a job in an environment where you will actually be called upon to use that exact information again...it is not worth it. I work for a pharmaceutical company and I dont use 99% of what I learned in school, which is good since I forgot at least 90% of it.

Most Colleges teach people what they need to know to get an entry level job in that field.

If I had it to do over again, I would have gone 100% business liberal arts.
From there you can go do whatever you want to do. I know docs worth millions with liberal arts degrees, they learned what they needed to in med school. I know men that own engineering businesses that arent engineers, they hire them to work for them... I have 2 friends that are structural engineers, they build the bridges and subway systems in major metro areas. we have had this conversation and they said what they learned in college was a joke and they went to leading schools for that.

Look... argue with me in 10 years when you are down the path you choose...and tell me if it was worth it then.

and while on campus, take advantage of all the extra curricular activities that you can find. I learned more about being an adult while president of my fraternity, interacting with the deans and president on campus. I was involved with the health dept and gave nutritional and sex ed talks on campus. sports etc... That was the best part of my education, but it was what I imposed on myself... if you want to learn something worth knowing... pick up Rich Dad Poor Dad, by robert Kiyosaki....Now that's what they should teach in school

Serendipity

Wasn't really trying to argue with you, so sorry if I came across that way...

As per the problem, you know the diameter, magnetic field, and the voltage. So I was trying to use the equation Bamadude suggested...will give it some more thought after I get a new cable box installed.

Serendipity

CAvolleyballguy wrote: »

and while on campus, take advantage of all the extra curricular activities that you can find. I learned more about being an adult while president of my fraternity, interacting with the deans and president on campus. I was involved with the health dept and gave nutritional and sex ed talks on campus. sports etc... That was the best part of my education, but it was what I imposed on myself... if you want to learn something worth knowing... pick up Rich Dad Poor Dad, by robert Kiyosaki....Now that's what they should teach in school

Hey, campus life is fun!

If I can't figure this out in another 2-3 days I'm going to give up on the problem.

ARGH!

Bamadude

Never give up... never surrender!!! (Galaxy Quest)

BaggedLancer

Always give up

Serendipity

BaggedLancer wrote: »

Always give up

I rarely give up!!

Might as well say give up on school and work at McDonald's.

Serendipity

I finally figured it out!! Well, with the help of some girl in my class

jdhdiggs

Welcome to the real world... Two hours on a single problem? Bah! Try two or three weeks on the same problem...

Lowell_M

appadv wrote: »

I finally figured it out!! Well, with the help of some girl in my class

Who are you kidding, there aren't any girls in upper level physics classes! (My B.S. is in Physics) That "girl" might be a dude!

OH.... and sorry, I can't help you with your problem... I moved from Physics to Engineering and then...three years ago... went through the brain sucking machine and into the world of Marketing. I'm much more comfortable there.

Serendipity

Haha, that's the only girl in the class. There's also only one girl in my EE class, but unfortunately she has a boyfriend

venomclan

LOL, my buddy in the Engineering classes always wandered over to my Liberal Arts side of the campus for the girls. There was no competition.
Venom

AsSiMiLaTeD

jdhdiggs wrote: »

Welcome to the real world... Two hours on a single problem? Bah! Try two or three weeks on the same problem...

Absolutely!

Don't listen to people who tell you that stuff you do in school won't help you down the road. Yeah, you may never use that specific knowledge. You don't go to school to learn a specific subject matter, although you do get that in the process, you go to school to learn how to think.

There have been many times I've spent a couple weeks on a single problem, and those hours spent in school working on a single Calc assignment for three hours really paid off.

Some problems you'll face aren't going to be problems you can just plug in to a computer and have it solve them for you. Believe it or not, some things you're actually going to have to think long and hard on, and exercises like this are going to help you.

Serendipity

In engineering classes, the ratio of guys to girls is like 80:1.