Engineering Project LC 2010

ldxo15wus6fpgm

freeze4real wrote: »

dude
the diameter is 10mm by gaug length 60mm.

What do I do with them.

And what's is pi x 25

this is my first year doing enginnering so I have no clue what youre sayin.

Amira Quaint Voter wrote: »

You're lucky I was at these today too :P

It gives you the diameter (10mm) above the chart in the papers, and using the area of a circle
pi X r^2

that's pi X 25.

If the maximum load is 142 kN, the tensil strength is 142kN/25pi. Whatever that works out to be is the answer.

Please tell me you're not serious? Please? :P

You're trying to work out the cross-sectional area of the end of a cylinder. That means you're trying to work out the area of a circle.

Pi means the mathematical symbol that looks like TT. It's the indefinite number starting with 3.14159... You know, the one you'd use in maths when you're working with circles? :pac:

Here's a pic, you can't really get a good pi from the keyboard...



The area of a circle = pi r^2 (say out loud "Pie r squared"). You should know this from maths :pac:
The not so obvious bit was ^ which is what you type when you mean "to the power of".

R = the radius of the circle. If the diameter is 10, the radius is half that so r = 5.

If you can't remember that the area = TT(r squared) it's in your log tables so don't worry about it (except for when you're going into your maths exam :P).

freeze4real

How do you know it's a clyinder or a circle.
My maths is poor as well pardon me.

freeze4real

Dude I get it now thanks to you. But when working out the straain it's extension divided by original length. I get the answer in e.g 0.4 divided by 60 = 6.66666667 x 10^-3 ( x 10 raised to power minus 3). Do I have to change it or multiply by a number to get a whole number.

ldxo15wus6fpgm

freeze4real wrote: »

Dude I get it now thanks to you. But when working out the straain it's extension divided by original length. I get the answer in e.g 0.4 divided by 60 = 6.66666667 x 10^-3 ( x 10 raised to power minus 3). Do I have to change it or multiply by a number to get a whole number.

I'd just round them up to something simpler. Seeing as 10^-3 = 0.00666...7 I'd round it to 0.006667. I don't have the papers in front of me this time but I assume it wants Young's modulus which is Stress/Strain

Now we have already worked out that the Stress = 142kN/25pi cm^2 (it's centimetres squared because it's an area value) which according to windows calculator = 1.81 kN per cm^2 (I've rounded that up)

So take 1.81/0.006667 as Young's modulus which according to windows calculator = 271.1998. So round that up to 271.2 and that's your answer.

If I were you I'd check these calculations though because I don't trust windows calculator with brackets etc. I'd much rather a proper scientific calculator.

freeze4real

Thanks I get this know.
I just want to ask by thermal equilibrium diagrams hoping that you know alot about it. How would you know what graph to draw bcuz as far I can can tell therre are differnt types of chart.

ldxo15wus6fpgm

freeze4real wrote: »

Thanks I get this know.
I just want to ask by thermal equilibrium diagrams hoping that you know alot about it. How would you know what graph to draw bcuz as far I can can tell therre are differnt types of chart.

Unfortunately I'm not doing that question so I can't help you there. I'm only doing Q1 (general + special topic - compulsory) Q2 (material testing) Q5 (welding) Q6 (plastics) and Q8 (mechanisms/devices).

I might do Q7 which is on machines, I'll chuck down whatever I know and hope for the best. The handy thing about engineering is the questions are pretty much the same every year and for some of them like Q5 on welding there's not too much they can ask anyway.

freeze4real

I'm doIn the same questions as you are except que 6 on plastics. What do you think they will ask on weilding.

ldxo15wus6fpgm

freeze4real wrote: »

I'm doIn the same questions as you are except que 6 on plastics. What do you think they will ask on weilding.

I reckon MAGS/TAGS welding will come up, but I'd learn the other 2 as well (MMA, Oxy-Acetylene). There's not much to it, just learn off how it works, is the electrode consumable, what are the advantages of a consumable electrode etc. And you probably need to learn the circuitry. For submerged arc welding you just need to know that it's submerged in flux and it's a normal arc with no gases (like MMA)

In MMA and MAGS/TAGS, you need to remember that it starts as high voltage AC current, goes through a transformer (becomes low voltage) and a rectifier (becomes DC) and then goes back the other way. You need to know how to draw the circuit for that too (this is probably the hardest bit of the welding question).

Definitely learn resistance welding (either seam or spot welding) because it always comes up. Just learn the basic principles though, like how the weld nugget is formed between the 2 pieces and a simpple diagram (no circuitry needed)

The question is called joining methods but nothing but welding has ever come up in Q5 so there's absolutely no point in learning brazing/soldering etc. you just need to know welding.

freeze4real

basically I should learn all about weilding. I'm pretty good with oxy acetylane weilding. And drawing a rectifier and a transformer ciruit as well as a smoothening capacitor is okay.

But the rest I'm poor.
I'm just gong through plastics and see if it's easy enough it will be good as a back up question.

Amira Quaint Voter wrote: »

I reckon MAGS/TAGS welding will come up, but I'd learn the other 2 as well (MMA, Oxy-Acetylene). There's not much to it, just learn off how it works, is the electrode consumable, what are the advantages of a consumable electrode etc. And you probably need to learn the circuitry. For submerged arc welding you just need to know that it's submerged in flux and it's a normal arc with no gases (like MMA)

In MMA and MAGS/TAGS, you need to remember that it starts as high voltage AC current, goes through a transformer (becomes low voltage) and a rectifier (becomes DC) and then goes back the other way. You need to know how to draw the circuit for that too (this is probably the hardest bit of the welding question).

Definitely learn resistance welding (either seam or spot welding) because it always comes up. Just learn the basic principles though, like how the weld nugget is formed between the 2 pieces and a simpple diagram (no circuitry needed)

The question is called joining methods but nothing but welding has ever come up in Q5 so there's absolutely no point in learning brazing/soldering etc. you just need to know welding.

Geard

Question 2,3,4 and 8.

ldxo15wus6fpgm

freeze4real wrote: »

basically I should learn all about weilding. I'm pretty good with oxy acetylane weilding. And drawing a rectifier and a transformer ciruit as well as a smoothening capacitor is okay.

But the rest I'm poor.
I'm just gong through plastics and see if it's easy enough it will be good as a back up question.

Pretty much!

Just remember if it has a G in it, it uses gas. Only oxy-acetylene uses flammable gas, the two with 'G' use the gas as a shield from oxidation.

The T in TAGS means tungsten - Tungsten won't melt. Once you know it's not a consumable electrode you know that a filler rod is used. A filler rod is also used in oxy acetylene as there is no electrode at all.

Plastics is pretty easy on the manufacturing processes side, you just need the names of each process and a simple sketch. I haven't looked at the molecular side of it but I remember it being complicated enough...

EDIT:

Geard wrote: »

Question 2,3,4 and 8.

I've been looking for the link for this for a while, I only just found it again. It gives a brief summary of what you need to know for each question. There are a couple of things that aren't in my textbook (I believe there is only one engineering book in Ireland :S) but a quick google of them did the job. Quicker than rooting through the book anyways!

Link

freeze4real

dude ur a legend.
I shud have you for lessons my teacher is useless all what he cares about is having a smoke.
Thanks alot man.

Amira Quaint Voter wrote: »

Pretty muc
Just remember if it has a G in it, it uses gas. Only oxy-acetylene uses flammable gas, the two with 'G' use the gas as a shield from oxidation.

The T in TAGS means tungsten - Tungsten won't melt. Once you know it's not a consumable electrode you know that a filler rod is used. A filler rod is also used in oxy acetylene as there is no electrode at all.

Plastics is pretty easy on the manufacturing processes side, you just need the names of each process and a simple sketch. I haven't looked at the molecular side of it but I remember it being complicated enough...

EDIT:



I've been looking for the link for this for a while, I only just found it again. It gives a brief summary of what you need to know for each question. There are a couple of things that aren't in my textbook (I believe there is only one engineering book in Ireland :S) but a quick google of them did the job. Quicker than rooting through the book anyways!

Link

ldxo15wus6fpgm

freeze4real wrote: »

dude ur a legend.
I shud have you for lessons my teacher is useless all what he cares about is having a smoke.
Thanks alot man.

Hahahaha my teacher is the exact same! Out for a fag break every 20 minutes without fail :pac:
No bother man, sure you're helping me too by making me check my facts!

Geard

Good man!!!!

freeze4real

Does anyone have a lnk fir accelerometers. I hav misplaced the sheet my teacher gave me.
Thanks.

Geard

Good luck every one!!!

kfpt

http://www.lit.ie/departments/seit-docs/Accelerometer-Eng-Leaving-Cert-Topic-2010.pdf

freeze4real

kfpt wrote: »

http://www.lit.ie/departments/seit-docs/Accelerometer-Eng-Leaving-Cert-Topic-2010.pdf

thanks so what d I have to know.
Basic priciples
diagrams

How many acclerometers can you deduce.
I can only deduce a basic accelromter and a piezoelectric one.

aerial man

How did everyone get on???

barry_boi

only a B2, gonna view it and maybe get it rechecked

trepasers

A1.....delighted !!

0987654321

UnionOfV wrote: »

Personally I don't have a problem with people doing sanding, soldering etc over the weekend before the deadline, but jesus picking the one large holiday before the deadline where the examiners will be descending on the schools in droves is suicide! You do realize if they make a trip to your school and find your project missing you fail the project and loose 25% off your overall engineering mark?

Aside, anyone have any ideas on how to make a base for my project? I was thinking a sheet of plywood + paint...

Bull****. We started ours a week before the deadline last year swear on anything