Mechanical Aptitude Test

[agjohn02]

Some of the questions are bad and I think two of them are straight up wrong. Therefore, I scored a 96%.


http://www.forddoctorsdts.com/quizzes/MechanicalAptitude.php

[Seth]

couple pulley ones got me, the first electrical diagram, the two pipes with water rising (higher pressure on B?), 48 is worded ****ty, the fan one i got but wasnt a good question, i missed the last one and shouldnt have.

88 percent. must be kinda tired, plus i didnt google.

[robertf03]

the one about the piston where it asked does vacuum suck the air in or atmospheric pressure push it down...

[agjohn02]

the one about the piston where it asked does vacuum suck the air in or atmospheric pressure push it down...


what about it?

[Jackasic]

i missed the one on the pipes, other than that, it was not that bad.

[DRAGOONRANCH]

missed the pipes and a planetary one

[RCcola55]

i suck at eletrical stuff

[StevenAg03]

which ones do you think were wrong john?

the piston one is kind of iffy....i think it should have been vacuum...

[agjohn02]

are you guys serious about the piston one. its right, maybe its a little misleading though.

the one with the gears (#7 maybe)
over drive, underdrive- i got
reverse, direct- i mixed up, but im convinced its their fault

the venturi (#44 maybe)
i understand bernoulli's principal and the venturi effect, but i dont think the fluid will rise in B. I understand where they are coming from since most illustrations of this effect show fluid rising in B and higher in A to demonstrate the pressure difference. if fluid rises in B, then that means that P2 is greater than PB and that carburetor, sandblaster, airbrush, etc. isnt going to work.

[agjohn02]

oh, and the one with the see saw and two blocks where the fulcrum is offset. i dont remember the details but they didnt have the correct answer there. i just figured out what they did wrong when calculating it and picked the answer they thought was right.

[robertf03]

What was the right answer on the piston one? I picked atmos pressure but I think its a bull**** question. I didn't see anywhere to view correct answers.

[agjohn02]

you can go back and look at them. it was atmospheric pressure.

[StevenAg03]

are you guys serious about the piston one. its right, maybe its a little misleading though.

the one with the gears (#7 maybe)
over drive, underdrive- i got
reverse, direct- i mixed up, but im convinced its their fault

the venturi (#44 maybe)
i understand bernoulli's principal and the venturi effect, but i dont think the fluid will rise in B. I understand where they are coming from since most illustrations of this effect show fluid rising in B and higher in A to demonstrate the pressure difference. if fluid rises in B, then that means that P2 is greater than PB and that carburetor, sandblaster, airbrush, etc. isnt going to work.

on the gears i see what your saying about reverse and direct because technically the direct one is reversing the direction. however, 'D' is definitely not a direct drive.

as for the see-saw one. if they were point loads on the ends, their answer would be correct...

[uglyota]

that piston one is BS. Would atmospheric pressure be sufficient to push the piston down and fill the cylinder with air if the crank didn't pull it down? Fawk no, the crank is pulling the piston down, creating a void and vacuum which pulls air in.

[DRAGOONRANCH]

that piston one is BS. Would atmospheric pressure be sufficient to push the piston down and fill the cylinder with air if the crank didn't pull it down? Fawk no, the crank is pulling the piston down, creating a void and vacuum which pulls air in.

If there was no atmospheric pressure, then it would stay a void.

[agjohn02]

that piston one is BS. Would atmospheric pressure be sufficient to push the piston down and fill the cylinder with air if the crank didn't pull it down? Fawk no, the crank is pulling the piston down, creating a void and vacuum which pulls air in.



and thats why you are not an engineer. so, does it create more of a vacuum when you put boost on it?

[robertf03]

it pushes the piston down and makes the motor spin

[fbronco86]

and thats why you are not an engineer. so, does it create more of a vacuum when you put boost on it?

And you are :flipoff2:

[DRAGOONRANCH]

And you are :flipoff2:


why, because he sucks?!?!

[DRAGOONRANCH]

oops, :flipoff3:

[agjohn02]

And you are :flipoff2:


as long as you dont count being able to do FEA by hand and matlab, yeah, i think so. i really suck at the academia way of doing FEA, never try it. just learn the software. speaking of which, i gotta go study.

[agjohn02]

on the gears i see what your saying about reverse and direct because technically the direct one is reversing the direction. however, 'D' is definitely not a direct drive.




yeah, i had the same logic and had them arranged that way, but for some reason i outsmarted myself and chaged the answer.

C- 1:1 but reverses direction
D- 2:1 with same direction

its a toss up as to which one you pick, with an edge on C being the direct if you dont sit and think about it too long.

[agjohn02]

it pushes the piston down and makes the motor spin


it puts the lotion on its skin or else it gets the hose again?

[uglyota]

If there was no atmospheric pressure, then it would stay a void.
no, if there was no atmosphere it would stay a void because it would already be a vacuum, but if the atmospheric pressure was 0 and all of a sudden the volume of the cylinder got bigger (by the piston going down), the pressure inside the cylinder becomes negative, ie vacuum, and air from outside rushes in to fill the vacuum.

[agjohn02]

:laughing:

[agjohn02]

i went back and looked at the question. its misleading yes, but if you read all the answers, the correct one should be obvious.

here you go eric, from your favorite source of information:

"On the first stroke (intake/induction) of the piston, as the piston descends it reduces the pressure in the cylinder, a mixture of fuel and air is forced, by at least atmospheric pressure, into the cylinder through the intake (inlet) port."

[uglyota]

I don't care what wikipedia says. The air is not forced in by atmospheric pressure. It is forced in by the vacuum that is the difference between the pressure inside the cylinder and the pressure outside the cylinder, which may be atmospheric pressure or it may be higher, it doesn't matter. The air would not be moving if the piston hadn't gone down, increasing the volume of the cylinder and creating a vacuum. PV/T=PV/T

[BMFScout]

Pv=nrt what?

[jerryg79]

i=prt!

[agjohn02]

Pv=nrt what?


i was gonna call him on that but if you rearrange the equation and take some stuff out, it right. its not a good argument though. im just saying that 3=3 and 2=2.

[agjohn02]

i=prt!


no, its V=IR

[jerryg79]

i could have sworn it was:

K = K*+IP+DRP+LP+MRP

[agjohn02]

U^ra=DuM@55

[nickas]

96% ya they are s***y questions

[jerryg79]

U^ra=DuM@55

funnyish

[DRAGOONRANCH]

My question is, can there actually be a negative pressure? Once there is nothing in a space, you can't get any more out of it, correct? So if there is no negative pressures, only 0 or more, than even in a vacuum there is some pressure.

[agjohn02]

My question is, can there actually be a negative pressure? Once there is nothing in a space, you can't get any more out of it, correct? So if there is no negative pressures, only 0 or more, than even in a vacuum there is some pressure.


pretty sure its a lost cause, ed. kinda like trying to tell democrats that abortion is murder, guns are not evil and islamofacists want to kill all of us

[FJAggie07]

funnyish

Negative ghost rider I give that a 6 out of 10 on the scale of funny. I chuckled.

[DRAGOONRANCH]

I am just trying to figure it out myself. I never did get into any of the physics classes other than what I learned in hikeskool and just general knowledge I have picked up over the years. I think it is an interesting subject.

You are right on the libs being so hard headed though. Like talking to a brick wall sometimes. It just makes you want to go club a baby seal.

http://static.flickr.com/118/251512004_492eef2a78_m.jpg

[DRAGOONRANCH]

And just so nobody thinks I am a total a$$hole..

http://www.myfilestash.com/userfiles/tooltime9901/Stop%20Clubbing%20Baby%20Seals.gif

[uglyota]

My question is, can there actually be a negative pressure? Once there is nothing in a space, you can't get any more out of it, correct? So if there is no negative pressures, only 0 or more, than even in a vacuum there is some pressure.
Ed that's the definition of vacuum. Negative pressure. I don't think it's like temperature, where absolute zero is defined by the point at which air molecules are no longer moving, and 0 C and 0 F are just human-dictated baselines. The baseline of pressure/vacuum is kind of the same way, as 0 is dictated by ambient conditions/14.7 psi/conditions at sea level at STP.
so here's another way of thinking about the original question: If you take the spark plug out of cylinder #1 at TDC, put a wrench on the crank and turn it a quarter turn, would you say "aw dang that there feels like a lack of atmospheric pressure," or would you say "that feels like vacuum?" Also, does a carb work just the same with atmospheric pressure on all sides (ie without a vacuum behind it) as it does with the vacuum on the manifold?
I understand that in an academic, "frictionless surface" type environment this question is probably fine. The cylinder appears out of nowhere and has no pressure in it. Atmospheric pressure might fill the cylinder. However, this test specifies at the beginning that it was designed to test the ability of tractor mechanics to learn/understand stuff. Vacuum created by increased volume in the cylinder definitely achieves that end better than "atmospheric pressure"
and for you douchebags who want to pick at my formula, it was Boyles' law, not the universal gas law, because n and r are constant in this case. John you should know that since you fancy yourself a diver.

[robertf03]

eric it is defined as 0,.there is absolute pressure where 0 is nothing, and gauge pressure, which is defined by 0 = ambient pressure.

[agjohn02]

i havent had a tank on my back in 5 years. i wish that werent the case.

14.7 is zero gauge psi. 0psi is 0 absolute psi is 0 psi.

i dont think boyles law takes temp into account. isnt it pv=pv

carbs work just mine with no manifold vaccuum. carbs work on bernoulli's principle. no manifold vacuum is ideal. thats max power since you have a full 14.7 psi pushing the intake charge into the cylinder.

[uglyota]

so it's impossible to pull more vacuum than -14.7 psi at sea level?

[agjohn02]

at STP, yup

[DRAGOONRANCH]

Ed that's the definition of vacuum. Negative pressure.

But that would be negative only to the baseline of atmospheric pressure. It would still have a measurable pressure if it could be put into a "perfect vacuum" <---big word, got it off of wiki :D

This is about as close to "chicken or the egg" debate as I have seen lately. This reminds me that I talked to my brother last night and he said he was haulin a load of "FEMA" meat to New Orleans last night. Why you say does this remind me of that. Was Nawlins full of looters and outright canadians, or did the hurricane produce a vacuum that they filled??? :gigem:

[uglyota]

What I quoted was the Combined Gas Law, not Boyles'. My bad.
So Ed I guess if you're talking absolute pressure, vacuum doesn't exist

edit: and the Canadians/looters/Canadian looters were definitely already there.

[agjohn02]

So Ed I guess if you're talking absolute pressure, vacuum doesn't exist



either way, your just creating a volume of lower pressure that the higher pressure volume rushes in to equalize.

[agjohn02]

edit: and the Canadians/looters/Canadian looters were definitely already there.


so the question stands:

did houston suck all the outlaws in or did katrina push them there?

[BMFScout]

so the question is:

did houston suck all the outlaws in or did katrina push them there?

Correct answer?

Who gives a fawk, it's Houston!! :flipoff2:

[DRAGOONRANCH]

We need a classics section like pbb. :gigem:

[agjohn02]

Correct answer?

Who gives a fawk, it's Houston!! :flipoff2:


precisely, i should have used formatting


did houston suck all the outlaws in or did katrina push them there?

[StevenAg03]

precisely, i should have used formatting


did houston suck all the outlaws in or did katrina push them there?


john this is still a trick question... :gigem:

[jerryg79]

its cool we sent them all north on the exhaust stroke (rita)

[Doug Krebs]

its cool we sent them all north on the exhaust stroke (rita)
:laughing:

[fbronco86]

Correct answer?

Who gives a fawk, it's Houston!! :flipoff2:

Jimmy I thought you were a University of Houston "COUGAR" fan :gigem:

[BMFScout]

Mike I thought you were straight, then I heard this really catchy tune that had your name in it!

[jerryg79]

Mike I thought you were straight,

what the hell gave you this idea? :D

[fbronco86]

Mike I thought you were straight, then I heard this really catchy tune that had your name in it!

Is that all you have to bust my balls about is some saying that you made up years ago. Even a prick like you can come up with something new.

You have to omit the cougar thing is funny. :gigem:

[jerryg79]

im laughing my ass off, OMIT!!!!!!!!! :laughing: :laughing:

while the cougar thing is funny you have a ways to go:
A) you dont bust people's balls with stuff that has already been said, and you didnt make up
B) if you do think its so awesome, you dont play it first, you lure them in and them crush them.

[agjohn02]

You have to omit the cougar thing is funny. :gigem:



:laughing: i had to quote that one :laughing:

[fbronco86]

:laughing: i had to quote that one :laughing:


I had fjaggie help me out with that one.

[BMFScout]

I'll "omit" it's funny, you got me good fawker.

The song is funny, and it pisses you off unlike what you're busting my balls for so it's double funny for me because I'm a *********in *********.

http://tamor.org/forums/showpost.php?p=69224&postcount=23

I would also say you can't bust people's balls about something you weren't there for and evidently hear secondhand from your friends.

[agjohn02]

jimmy, did you hook up with, and i quote:

"An older woman who frequents clubs in order to score with a much younger man. The cougar can be anyone from an overly surgically altered wind tunnel victim, to an absolute sad and bloated old horn-meister, to a real hottie or milf. Cougars are gaining in popularity -- particularly the true hotties -- as young men find not only a sexual high, but many times a chick with her **** together."

[BMFScout]

Mike's gay

[agjohn02]

or was it one of these:

"(see also hunt, prowl, corner, pounce). Noun. A 35+ year old female who is on the "hunt" for a much younger, energetic, willing-to-do-anything male. The cougar can frequently be seen in a padded bra, cleavage exposed, propped up against a swanky bar in San Francisco (or other cities)waiting, watching, calculating; gearing up to sink her claws into an innocent young and strapping buck who happens to cross her path. "Man is cougar's number one prey""

[jerryg79]

I would also say you can't bust people's balls about something you weren't there for and evidently hear secondhand from your friends.

i was going to go with that one too.

[Sharpe]

I'll "omit" it's funny, you got me good fawker.

The song is funny, and it pisses you off unlike what you're busting my balls for so it's double funny for me because I'm a *********in *********.

http://tamor.org/forums/showpost.php?p=69224&postcount=23

I would also say you can't bust people's balls about something you weren't there for and evidently hear secondhand from your friends.
I've never heard the whole song before! Every time Jimmy tries to sing it Mike gets pissed and starts chasing people :laughing:

[agjohn02]

nevermind jimmy, either it didnt happen, or she wasnt a "cougar" by definition:flipoff2:

"A woman in her sexual prime who prefers to hunt rather than be hunted. A cougar's victims are usually under 25, as cougars prefer to mate with men who still have hair. Cougars generally feed and then continue hunting, as they enjoy role reversal."

[FJAggie07]

I had fjaggie help me out with that one.

:flipoff2:

[fbronco86]

I'll "omit" it's funny, you got me good fawker.

The song is funny, and it pisses you off unlike what you're busting my balls for so it's double funny for me because I'm a *********in *********.

http://tamor.org/forums/showpost.php?p=69224&postcount=23

I would also say you can't bust people's balls about something you weren't there for and evidently hear secondhand from your friends.

I think this is going to affect our friendship.

[mudtoy67]

Mike, there are still donuts by my office. Have a sprinkled one and a smile. :)