Two more dive physics problems

[n03]

The point of learning dive physics isn't to be able to regurgitate exact information you've received, it's to be able to apply it when you need to. If you understand the principles you were supposed to learn in the course you should be able to figure out how to solve the problems. These are the exact two problems I struggled with on this exam, and they're not easy, but the information you need to solve them is in the book. Nowhere is the question asking you to come up with the "real life" answer including safety regulations, it's asking for the math answer to the question.

Applying information I've received when I need it! No kidding! The book doesn't mention lift lines a single time. Nor does it define the total crushing force. Or a single word about using lift bags (which I'm trying to get clarifications on in a separate thread). And if it is mentioned somewhere, I'd appreciate if someone points me to it because I can't find it.
The pure math answer to question #1 is 7200 lb. This is not one of the available answer choices. I arrived at that number on my own, and then it wasn't clear how to apply that information to selecting a lift line.
As for question #2, the first answer I arrived at on my own is 14,160 lb (by multiplying total surface area of the box by absolute pressure at that depth; then I started thinking that maybe they are asking about the pressure that is exerted on the top side of the box, but then the orientation of the box would matter... and it's actually still not clear to me whether hydrostatic pressure would be equal on all 6 sides of the box). I didn't know that we only need to factor in the hydrostatic pressure, and not include the pressure of the atmosphere, which in all or most other problems we do need to factor in. This is not explained in the book. Not to mention that, as someone pointed out, it actually matters for a box that size if it's the top or the bottom of the box that's at 20 ft.

These aren't homework questions, they're from the final exam of the course, which can (and often is in my experience) given as a take home exam. If he's not able to work them out on his own, that's information that would be relevant to an instructor certifying that the student has passed the physics session of the course or not. Unless the exam has already been turned in (in which case the instructor should have/would have gone over the questions students got wrong) he's basically cheating on the exam.

Oh please! Cheating on a take home exam by asking other people for help. Particularly with poorly worded questions where it's not even clear what is being asked - and this has been the opinion of several people on this forum. I don't see how it matters from an ethical stand-point whether I find answers in the book or from other people as long as I make an effort and learn the material.

By the way, I'm curious how you would defend some other questions that have bizarre answer choices, e.g.:

Corals containing stinging cells are in the group called:
1) Coral reefs
2) Soft corals
3) Fire corals
4) Brain corals

The book actually has a sentence: Although all corals contain stinging cells, the group called "Fire corals" is the most troublesome to divers. This phrase basically eliminates all available answer choices. The correct answer should be "all corals contain stinging cells". The closest option is "coral reefs", but that's not a group of corals, it's an ecosystem (well, whatever they mean by group, right?! It's not exactly scientific to begin with). So it seems to me that they mean "Fire corals" as the correct answer, but soft and brain corals also contain stinging cells.

Here's another one:
Permanent hearing loss and ringing in the ear are most likely to be the result of a ruptured:
1) Round window
2) Eardrum
3) Oval window
4) Semicircular canal

Both round and oval window rupture will produce hearing loss and ringing in the ear (and probably so will rupture of the semicircular canal!). Interestingly, in the metric version of this test the the two options are included as part of the same answer choice. The book does say that rupture of the round window is more common than rupture of the oval window, so I would go with that answer, but this is really twisted logic!

I'm not saying that all questions are bad. Some were interesting and fun to work through, and some of them are actually necessary to know the answers to in order to practice safe diving. But if there was a real physicist or biologist on the test-writing team the test would look quite different from what it does now.

 

[Akimbo]

There is simply no excuse for such poorly phrased questions to make it into print... let alone into a re-print. You would think that they would revise them after the first 30 students with more knowledge of physics and language called them on it.

 

[Rich Keller]

These aren't homework questions, they're from the final exam of the course, which can (and often is in my experience) given as a take home exam. If he's not able to work them out on his own, that's information that would be relevant to an instructor certifying that the student has passed the physics session of the course or not. Unless the exam has already been turned in (in which case the instructor should have/would have gone over the questions students got wrong) he's basically cheating on the exam.

That must not be much of a training agency. You are far more concerned about this then they are assuming you are right about this being a final exam.

 

[kmurray719]

Applying information I've received when I need it! No kidding! The book doesn't mention lift lines a single time. Nor does it define the total crushing force. Or a single word about using lift bags (which I'm trying to get clarifications on in a separate thread). And if it is mentioned somewhere, I'd appreciate if someone points me to it because I can't find it.
The pure math answer to question #1 is 7200 lb. This is not one of the available answer choices. I arrived at that number on my own, and then it wasn't clear how to apply that information to selecting a lift line.
As for question #2, the first answer I arrived at on my own is 14,160 lb (by multiplying total surface area of the box by absolute pressure at that depth; then I started thinking that maybe they are asking about the pressure that is exerted on the top side of the box, but then the orientation of the box would matter... and it's actually still not clear to me whether hydrostatic pressure would be equal on all 6 sides of the box). I didn't know that we only need to factor in the hydrostatic pressure, and not include the pressure of the atmosphere, which in all or most other problems we do need to factor in. This is not explained in the book. Not to mention that, as someone pointed out, it actually matters for a box that size if it's the top or the bottom of the box that's at 20 ft.



Oh please! Cheating on a take home exam by asking other people for help. Particularly with poorly worded questions where it's not even clear what is being asked - and this has been the opinion of several people on this forum. I don't see how it matters from an ethical stand-point whether I find answers in the book or from other people as long as I make an effort and learn the material.

By the way, I'm curious how you would defend some other questions that have bizarre answer choices, e.g.:

Corals containing stinging cells are in the group called:
1) Coral reefs
2) Soft corals
3) Fire corals
4) Brain corals

The book actually has a sentence: Although all corals contain stinging cells, the group called "Fire corals" is the most troublesome to divers. This phrase basically eliminates all available answer choices. The correct answer should be "all corals contain stinging cells". The closest option is "coral reefs", but that's not a group of corals, it's an ecosystem (well, whatever they mean by group, right?! It's not exactly scientific to begin with). So it seems to me that they mean "Fire corals" as the correct answer, but soft and brain corals also contain stinging cells.

Here's another one:
Permanent hearing loss and ringing in the ear are most likely to be the result of a ruptured:
1) Round window
2) Eardrum
3) Oval window
4) Semicircular canal

Both round and oval window rupture will produce hearing loss and ringing in the ear (and probably so will rupture of the semicircular canal!). Interestingly, in the metric version of this test the the two options are included as part of the same answer choice. The book does say that rupture of the round window is more common than rupture of the oval window, so I would go with that answer, but this is really twisted logic!

I'm not saying that all questions are bad. Some were interesting and fun to work through, and some of them are actually necessary to know the answers to in order to practice safe diving. But if there was a real physicist or biologist on the test-writing team the test would look quite different from what it does now.

I never claimed the book or the questions were well written. We actually edited the text to correct many cases of incorrect information during my class and sent it to SSI, though I doubt they did anything with it. It was probably the worst edited/written text I've ever used. Some of the exam questions are definitely ambiguous, some are worded terribly, and we found a few on the exam that the "correct" answer was just wrong. But I've found most scuba texts/exams to not be much better I don't have the text in front of me (or even accessible to reference) but I do know that I had all the pieces of information I needed to solve all the test problems. It's possible I just had an extra awesome instructor and the information came from my notes vs. the book, but shouldn't your instructor have prepped you for the exam they knew you'd be taking? The point of an exam is to test if you've already learned the information. If you can't solve the questions then you didn't get out of the course what you were intended to, whether it's due to the text or your instructor. It's great that you're trying to learn this now and asking here, but that has nothing to do with whether getting help solving the problems from other people is cheating. I have zero investment in whether whether you pass or fail your exam, or whether you get a cert ethically or not. But unless your instructor or SSI told you that it was fine to ask for input from others to complete the exam, it is cheating, plain and simple. You're turning in the exam answers as your own work when they're not.

 

[Akimbo]

... But unless your instructor or SSI told you that it was fine to ask for input from others to complete the exam, it is cheating, plain and simple. You're turning in the exam answers as your own work when they're not.

I don’t see it that way. Any test is about understanding the subject and I bet n03 understands the subject far better than s/he ever would from reading the text alone.

 

[kmurray719]

I don’t see it that way. Any test is about understanding the subject and I bet n03 understands the subject far better than s/he ever would from reading the text alone.

My viewpoint is also based on the fact that we were explicitly told we were to complete the exam without help, that it was to be all our own work, and that was the directive from SSI in regards to allowing the exam to be a take home vs. done in the classroom. I recognize that the OP may not have gotten those specific directions, however, I have never heard of a scuba exam where asking others for help is the norm.

 

[n03]

It's possible I just had an extra awesome instructor and the information came from my notes vs. the book, but shouldn't your instructor have prepped you for the exam they knew you'd be taking? The point of an exam is to test if you've already learned the information.

The point of a take home exam is to test if you've already learned the information, and if you haven't learned some of it then to learn it. If the point was to just test if you've already learned the information then the exam would be administered in class.

It's great that you're trying to learn this now and asking here, but that has nothing to do with whether getting help solving the problems from other people is cheating. I have zero investment in whether whether you pass or fail your exam, or whether you get a cert ethically or not. But unless your instructor or SSI told you that it was fine to ask for input from others to complete the exam, it is cheating, plain and simple. You're turning in the exam answers as your own work when they're not.

I started this thread because neither the SSI book nor my class notes contain the required information to arrive at an answer to these problems with confidence (for the money I paid to SSI they could have at least published a comprehensive reference with practice problem sets). What options do I have to cover the gap? Search the internet and other references or ask others for help. You contributed exactly zero to my understanding of dive physics, and you came into this thread to criticize and accuse me of cheating. You also wasted my time. This is how off-topic arguments start on forums, and I don't want to be part of it.

 

[kmurray719]

The point of a take home exam is to test if you've already learned the information, and if you haven't learned some of it then to learn it. If the point was to just test if you've already learned the information then the exam would be administered in class.

I started this thread because neither the SSI book nor my class notes contain the required information to arrive at an answer to these problems with confidence (for the money I paid to SSI they could have at least published a comprehensive reference with practice problem sets). What options do I have cover the gap? Search the internet and other references or ask others for help. You contributed exactly zero to my understanding of dive physics, and you came into this thread to criticize and accuse me of cheating. You also wasted my time. This is how off-topic arguments start on forums, and I don't want to be part of it.

You don't know any more about physics from me, but you now know that there are things that are taught in the course that you should have been taught in your course that weren't. What options do you have? If you didn't get the information you were supposed to from the class, hold the instructor and shop accountable.Go in and say "I did not get the information I was supposed to from this course and was not able to solve the test problems. Why?" Maybe you'd get another class session from a different instructor to get up to speed, maybe the instructor would get some counseling from someone about what the course was lacking and be held accountable for doing it differently going forward, maybe nothing but the shop knowing a student was dissatisfied would happen. I have no idea, but neither do you if you don't bring it up.

 

[Jim Lapenta]

I have had this discussion with students with both SEI and SDI/TDI exams as they are written. Whenever I find a mistake I correct it, reprint the exam with the corrections, and use it for the next student.

I have had students who are obviously more qualified in some areas than the people who wrote the exam. So when a question is pointed out as wrong, badly worded, ambiguous, or just plain stupid it goes bye bye and is replaced with one that makes sense, still covers the material, and does not look like something from a semi literate goober.

When you allow a student to take home any kind of work or test to say they are cheating when they are actually researching the answer in a logical, intelligent, and thoughtful manner -including asking for help from those with what is obviously more sense than those who wrote the exam- it is certainly not cheating. It's an example of excellent problem solving skills and making use of available resources.

Knocking their head against a wall trying to find answers that do not exist in the text or have not been covered in the classroom and are therefore not in their notes, is stupid. When I give a student homework I expect them to use every available resource to complete the assignment in a way that helps them understand the material. I actually give them the website address for scubaboard in the first class so they can come here for answers.

If this was actually a real test the OP was taking and it was supposed to be done as a test with no help then you don't let the student take it home. That's just common friggin sense. The OW test I give students is closed book. After that it depends. I would rather have a DM do an open book test on some items to show me they are not just guessing at answers or luckily picked the right one. That they actually have the sense to look go and find them in the material and be sure of that knowledge is more impressive.

It's like formulas for gas management and dive physics. Rather than have someone screw up an exam because they put a number in the wrong place I want them to have their formula sheet out and them get used to using it so they don't make a stupid mistake.

I still use tables for all classes and I make my students use them. Carefully so that they don't make mistakes.

Once you are an instructor there are some items you just know and rattle off like your own address or phone number. But there is a limit to that based on the classes you offer and the questions that students come up with.

Better to stop, think, and figure out that you really don't have the answer to that one or are not 100% sure and tell the student that. Then demonstrate to them that you care enough to crack a book, make a phone call, Google it, or come here and ask so that they see that you are not just blowing smoke up their hind end.

It also demonstrates that even for instructors, as godly as we think we are sometimes, we can be stumped and need to ask for help. Just as they should be able to admit the need help.

If you are allowed to take the exam home, it's not a real exam. It's little more than homework and to complete it you use all the resources you can.

---------- Post added August 15th, 2014 at 06:11 PM ----------

Oh and for what it's worth, some things are covered in one agency's materials that are not in others. So going outside the box and finding the answers from those other agency's materials when it's needed and getting the perspective of instructors outside your own agency is a smart thing to do.

 

[rhwestfall]

absolutely, but to merely give him the answer isn't helping him......