1,001 questions about the ASTB (post your scores & ask your questions here!)

[madmax]

Thanks.

 

[airhorn]

I'm having some trouble determining the mechanical advantage of compound pulley systems. Going through the ASTB flashcard gouge provided by the forum, I came across a few pulley questions that were confusing. For example,

In this question it asks how many stands of rope is the load supported by:

The answer is 3.

In the next card, it provides the same image but asks "if the pull of the truck in the diagram in 100 ibs, what is the maximum weight of the object"-which the answer is 400.

My question in how do you determine which strands of rope in the system count towards the overall mechanical advantage. It was to my knowledge that the MA of a pulley system is the amount of supporting ropes. If this was the case then the answer to the latter question would be 300. Are the flashcards wrong or am I missing something?

 

[GreenLantern330]

I'm having some trouble determining the mechanical advantage of compound pulley systems. Going through the ASTB flashcard gouge provided by the forum, I came across a few pulley questions that were confusing. For example,

In this question it asks how many stands of rope is the load supported by:

The answer is 3.

In the next card, it provides the same image but asks "if the pull of the truck in the diagram in 100 ibs, what is the maximum weight of the object"-which the answer is 400.

My question in how do you determine which strands of rope in the system count towards the overall mechanical advantage. It was to my knowledge that the MA of a pulley system is the amount of supporting ropes. If this was the case then the answer to the latter question would be 300. Are the flashcards wrong or am I missing something?

You're right about the MA. It's a force multiplier so the answer should be 300. If the cards you're referring to are the ones found online, they're not that accurate or great at all. I wouldn't use them. I did have a little trouble figuring out which ropes are actually used because I had read that only moveable pulleys contributed to mechanical advantage (never figured out what a moveable pulley is). My guess from the picture you posted would be the first 2 ropes from left to right and then the 4th one are the ones doing the work. Not sure if this is right, but I think it is. I know the pulley at the bottom next to "to truck" doesn't do anything.

Anyone please feel free to correct me if I'm wrong.

 

[VNE]

The way I solved these on my test was to simply, "follow the rope." Place your finger on the screen over the diagram where the rope is tied to the pulley. Now, follow the rope with your finger, making note of every time you make a >90 degree turn. Do this until you end at the truck. You should have counted to 3...that's the MA. If you multiply the MA by the weight, you will get the max weight that can be lifted in the system...300 lbs.The online ASTB cards are terrible. I stopped using them in order to avoid confusing myself.

@GL...Moveable pulleys as referenced by the exam as pulleys that are...well...moveable. But more specifically that are not attached to at a fixed point. Haha. The aforementioned diagram has only 1 moveable pulley (the one that's closest to the weight.) Notice that the other 3 pulleys are attached to the wall or floor? Since they are affixed to non-moving things, they will be held in place.

On the test, I saw a similar question, except it asked something like, "If the truck moved forward by 15 feet, how high would the weight travel?"

 

[GreenLantern330]

@GL...Moveable pulleys as referenced by the exam as pulleys that are...well...moveable. But more specifically that are not attached to at a fixed point. Haha. The aforementioned diagram has only 1 moveable pulley (the one that's closest to the weight.) Notice that the other 3 pulleys are attached to the wall or floor? Since they are affixed to non-moving things, they will be held in place.

On the test, I saw a similar question, except it asked something like, "If the truck moved forward by 15 feet, how high would the weight travel?"

Haha, thanks. When I asked what moveable pulleys were, I guess I meant how to tell if one was moveable or not.. every time I'd look at a practice test or a question with pulleys I'd think "but they all look anchored to the ground/wall/ceiling..." That helps though.

For the example you provided, could you explain how to solve that? I thought I had a grasp on pulleys...apparently I don't haha.

 

[MGoBrew11]

@ GL, when you think about pulleys, you also have to remember how much rope will be need to be used. So in VNE's example, he asks how high will the weight be lifted if the truck moves 15 feet.

If the mechanical advantage is 3, that also means that you will only move the weight 1/3 as far as you pull it. So in this case, the truck pulls the rope 15 feet. If we divide that by 3, we get 5. The weight is lifted 5 feet from the ground in this case.

 

[GreenLantern330]

@ GL, when you think about pulleys, you also have to remember how much rope will be need to be used. So in VNE's example, he asks how high will the weight be lifted if the truck moves 15 feet.

If the mechanical advantage is 3, that also means that you will only move the weight 1/3 as far as you pull it. So in this case, the truck pulls the rope 15 feet. If we divide that by 3, we get 5. The weight is lifted 5 feet from the ground in this case.

So the mass of the weight doesn't matter? Just the distance and mechanical advantage?

 

[MGoBrew11]

So the mass of the weight doesn't matter? Just the distance and mechanical advantage?

Correct.

The question is not asking "Will the object move?" or "How much effort is required to move the object?" If that were the case, the weight of the object definitely matters (as does the amount of work being done). That is more along the lines of the original question (ie if the object weighs 100 lbs and the MA is 3, how much effort do you have to put in to move the object? 33.33 lbs).

Since VNE's example question assumes that the object WILL move, the only thing that matters is how much rope will be displaced compared to how high the object will rise with a MA of 3. In this case, the answer is 5 feet in height for 15 ft of rope pulled by the truck (or 6 ft if the truck pulls 18 and so on).

 

[GreenLantern330]

Correct.

The question is not asking "Will the object move?" or "How much effort is required to move the object?" If that were the case, the weight of the object definitely matters (as does the amount of work being done). That is more along the lines of the original question (ie if the object weighs 100 lbs and the MA is 3, how much effort do you have to put in to move the object? 33.33 lbs).

Since VNE's example question assumes that the object WILL move, the only thing that matters is how much rope will be displaced compared to how high the object will rise with a MA of 3. In this case, the answer is 5 feet in height for 15 ft of rope pulled by the truck (or 6 ft if the truck pulls 18 and so on).

Thanks, that clears it all up!

 

[airhorn]

much thanks! getting ready for ASTB round 2 at 1000 next mon

 

[starpunch]

Not sure what value of wisdom this has, but I found a quote on the nyusn blog from a recruiter/winged aviator in regards to the ASTB.

"A lot of people write in asking if they are competitive for selection on the boards. I made up a profile of someone off the top of my head of who I can see being selected for a position. I'll tell you straight off that your ASTB scores (in my mind at least) are what get you in, the Navy may deny it and say that it is the "whole person" but ASTB is the money maker. Second I feel are your college grades, I particularly don't agree with this for various reasons. Firstly it is because I don't think much for formal education in general. I hated college and thought it was a complete waste of time, I learned very little and if I could do it all over again I probably wouldn't have gone myself. But my opinions are constantly reinforced. How? I have given over 100 ASTB exams since I started working as a recruiter and have seen no more than 14 over 60 on the OAR. Meanwhile most all applicants have a GPA above a 3.0. In turn you are above average for four years and then cannot score above average on a test that is basic SAT knowledge. That tells me grades are inflated beyond reliability and also that there are too many colleges and too many people who attend them.

And the Navy is not an environment in which book knowledge translates into success in the field. The best Officers I have met have been ones who were either bored with school or didn't score very high. BUT they were great in pressure situations and ones which demanded a proper decision with little information. But I am getting off track...

All that lip service about whole person comes in when there are two applicants who have the same test scores and the same college grades. At that time if you have something extra in your background then it will be the deal breaker but that is the only time I can see it having any effect. And in regards to LORs, unless it is from a Senator, Congressman, Jamie Dimon, Obama....real heavy hitters in the world, people who could make a phone call and get something done; well they aren't going to mean much at all.

Jack Huntington has a 3.4 GPA from Michigan. On his ASTB he scored a 63 with an AQR of 8, and sevens on the other two sections. He played two varsity sports in high school and was the captain of one, of which he also made All State in his senior year. He had a summer job as a base ball coach up until his senior year when he interned and eventually worked at said job for two years. As witnessed by his scores he has been curious about aviation, ships and mechanics his whole life but possesses no formal training in any of those fields. He is physically fit and stays so working out five days a week.

Now the big question is if you are not this guy how do you make up for it? The only answer is through the ASTB. The ASTB is who you are now, not who you were. Also it has been designed to gauge how well you will do in OCS. Basically the OAR portion is a judge of how a candidate will fare with the academic portion at OCS. The aviation portions determine how well you will do in API which determines how well you will do in flight school. After having gone through them all I can say that it is pretty spot on."

That quote seems retarded. So in essence the ASTB is all that matters and what people did in their life doesn't matter to the Naval boards. If one deduces what is written, a junkie can ace the ASTB, therefore he is a officer material. If that is the case, then they would have declared ASTB as the main and only entry.
But then again, they require GPA and many letters, so it would indicate that they do want to read the other material such as GPA. People do well on tests but have lousy GPAs indicates most times that the person is lazy and of unreliable/unethical character. Not always the case, but true most of the time. Many people have tons of experience that is applicable to the Navy. I don't disagree the test is important, but its value is not a sole factor.

 

[MGoBrew11]

That quote seems retarded. So in essence the ASTB is all that matters and what people did in their life doesn't matter to the Naval boards. If one deduces what is written, a junkie can ace the ASTB, therefore he is a officer material. If that is the case, then they would have declared ASTB as the main and only entry.
But then again, they require GPA and many letters, so it would indicate that they do want to read the other material such as GPA. People do well on tests but have lousy GPAs indicates most times that the person is lazy and of unreliable/unethical character. Not always the case, but true most of the time. Many people have tons of experience that is applicable to the Navy. I don't disagree the test is important, but its value is not a sole factor.

Not retarded at all. The OFFICER that runs that blog is one of the most experienced in the business (he is "sir" to you, not "retarded"). You should take what he has to say as very accurate, as many others here will agree.

I understand what you are saying. There is absolutely more to getting a pro rec than the ASTB, but don't underestimate its value. It tells the Navy who you are in the moment. I go to a very respectable state school (considered more than respectable by some) and have a more than a respectable GPA. However, I only did slightly better than average my first time around on the ASTB and was not recommended by the boards the first time applied. The second time I took the ASTB I did great (8/8/9 61) but I am still waiting for the boards to even meet (they might not even meet until September!)

The moral of the story is: the ASTB is very important and do awesome on it the first time because you never know what can happen.

- and don't call that blog retarded, it is usually spot on. Not to mention it is run by a Naval OFFICER that has served his country and deserves respect. He knows what he is talking about.

 

[starpunch]

Not retarded at all. The OFFICER that runs that blog is one of the most experienced in the business (he is "sir" to you, not "retarded"). You should take what he has to say as very accurate, as many others here will agree.

I understand what you are saying. There is absolutely more to getting a pro rec than the ASTB, but don't underestimate its value. It tells the Navy who you are in the moment. I go to a very respectable state school (considered more than respectable by some) and have a more than a respectable GPA. However, I only did slightly better than average my first time around on the ASTB and was not recommended by the boards the first time applied. The second time I took the ASTB I did great (8/8/9 61) but I am still waiting for the boards to even meet (they might not even meet until September!)

The moral of the story is: the ASTB is very important and do awesome on it the first time because you never know what can happen.

- and don't call that blog retarded, it is usually spot on. Not to mention it is run by a Naval OFFICER that has served his country and deserves respect. He knows what he is talking about.

Actually it is retarded and you are as well because you fail to understand reading comprehension. I only disputed what is written. not the messenger. In any event, blogs are not officially endorsed by the Navy. I never said the test is not important. It is important, however so are the other areas. And your "respectable school" does not matter. It is contradictory you mention the test but go nuts about your "respectable school"
As I said, if the test is the sole factor, then a junkie is officer material just because he did well. There is a reason why many other factors matter.

 

[VNE]

No one is saying the other sections don't matter, but the ASTB is the most heavily weighted part (especially for sna/snfo.) The Navy has conducted research among her better officers/pilots to see what they had in common in order to phase out the "not-as-competitive" applicants. They found a tight correlelation among them with high ASTB scores. I take it from all of your complaining that you didn't do so hot on your ASTB. There are several others on this forum who scored "average" at best on their test. However, instead of crying "Waaahhh, it's not fair" they are buckling down and studying harder to meet the competition. I respectfully suggest that you do the same.

 

[MGoBrew11]

Actually it is retarded and you are as well because you fail to understand reading comprehension. I only disputed what is written. not the messenger. In any event, blogs are not officially endorsed by the Navy. I never said the test is not important. It is important, however so are the other areas. And your "respectable school" does not matter. It is contradictory you mention the test but go nuts about your "respectable school"
As I said, if the test is the sole factor, then a junkie is officer material just because he did well. There is a reason why many other factors matter.

Well I really wasn't trying to start anything. I brought up the school because I realize that the school you go to doesn't matter. That's the point. The ASTB can test one's basic math, reading and reasoning skills without looking at GPA or school.

You can go to Harvard and have a 4.0 but only get a 45 on the ASTB. You probably aren't going to get picked up.