How was the test (1 Viewer)

[thehootman]

Multiple Choice

1) A [100% right]
2) A (my intial thought was hydrostatic pressure equal in all directions, but it may be c as pressure varies with height)
3) C [wild guess but figured it out when i left and answer is definatatly B]
4) B
5) B [100%]
6) A [100%]
7) D [100%]
8) A [i got it somehow not sure]
9) B [100% since any line that is perpendicular or parallel to the page is true length]
10) D [my mate said he got it lucky guess since my original answer was C but i thought it was too easy for quesiton 10.

Im hoping for 7 or 8 / 10 for multiple choice.
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* For the test I didnt get the distance up the slope question calc
* For the graphical calculation near the end I think i got 1400N at 55 degrees I think
* The Battery question I couldnt make out if they were configuration I just assumed in series and got 24
.....................................................................................................
Overlall didnt like the test but I answered everything fully and hopefully some of my bullshit responses pay off

1) is not a, most definetly not. Think about it, if you have a hardened steel and then temper it, you sacrifice some hardness (less hardness) for some more toughness so it is useful (more toughness).
2) is C. Although the difference in pressures would be very little, there still would be some difference.
3) I foolishly put B. Think 3 force rule... if a body with 3 forces is in equilibrium then the forces pass through a single point (in this case). Therefore it cant be anything but 50 degrees (C).
4) Is D - you will notice the design is such that the ceramic is in compression.
5)B
6)A
7)D
8)B. Double shear = 2x area of single shear ie the single shear has half the maximum load
9)B
10) If it is 1/4 scale then the dimensions are 1/4 of the size, which means the area is 1/16 of that of the full scale. Therefore I agree with you - D.

Woot 100th post

 

[Horyd]

the answer to 2 is not C people. It is A. Pressure variation with height is not in the syllabus, but equal pressure acting in all directions is, hence the answer is A.

I got 28.5m for the slope thing too, but for the compressive force in the winch i got 1568N, because i used the 900N value in summing forces horizontal to the cosine component of the beam B since the winch wire cannot take horizontal loads. I think both graphical and this method will be marked correct for that question. The answer to the batteries q is 12V (like the guy above me said), because its two pair of batteries (in series) put in parallel. Oh and i got the sine wave for the demod as well.

Overall, i thought the test has pretty easy

 

[thehootman]

the answer to 2 is not C people. It is A. Pressure variation with height is not in the syllabus, but equal pressure acting in all directions is, hence the answer is A.

I got 28.5m for the slope thing too, but for the compressive force in the winch i got 1568N, because i used the 900N value in summing forces horizontal to the cosine component of the beam B since the winch wire cannot take horizontal loads. I think both graphical and this method will be marked correct for that question. The answer to the batteries q is 12V (like the guy above me said), because its two pair of batteries (in series) put in parallel. Oh and i got the sine wave for the demod as well.

Overall, i thought the test has pretty easy

Not in the syllabus eh? Then why is it that I am currently seeing P=Po + pgh on my equation sheet? I think you'll find that it IS in the syllabus.

 

[Horyd]

really? even still, im not sure what they are trying to do there, they are two conflicting principles in this sense. Considering that perhaps i am wrong, but i can see this argument occuring between the markers, i'm not sure which way they'll fall though

 

[chrisayoub90]

heres my multiple choice answers,
1- C, this was pretty obvious wasnt it.
2- A, im pretty sure pascal or one of those kooks said pressure in an enclosed fluid exerts an equal force at all points.
3- C , didnt anyone see the TO SCALE and figured you could draw them concurrent and bang theres your 50 degrees.
4- D was my answer cause ceramic is strong in compression although i dno if its the most relvant answer
5- B, a quick inverse tan solves this one.
6- A easy small bit of maths.
7- D, Brittle to ductile.
8- had B but wasnt too sure.
9- B was my answer, one from the top view and one from the bottom.
10- my answer was C. wasnt tooo sure either, i figureed if u had 4 of the 1/4 scaled pieces it would be 4 times as strong.

i got 28. something for the hill one too, pretty happy bout that one.
the winch question i had 1500 and something aswell using a force diagram and cos54 or somethign, how did everyone get these other answers?

how different was the test but, alot of different style questions opposed to the past hscs, alot of people will prolly get thrown off by that.

 

[Itike]

that exam was a LOT harder than i thought it would be. couldnt do the car going up the hill. anything on telecommunications was hard becuase for that whole topic out teacher just made us read sheets because we only has like 3 weeks to do it. i got 70% in trials but i reckon 60% in that one. i drew a force diagram for the winch question but just as i finished it i realised it had asked for the reaction at the joint- not the force in the beam. i am just glad i do 12 units and that wont count!

 

[Horyd]

C
A (could be C, maybe there is special significance in the word "levels" in the question, not sure) EDIT: im thinking A more now, considering the fluid inside the vessel is gas, the pressures will so close together because the weight isnt substantial enough, so im thinking the readings will be the same
C
D
B
A
D
B (because the load would now be concentrated on a single area, not two)
B
D (im pretty sure "scale" refers to diameter/radius, so the area difference is then squared, so its 16 times the original load)

for the bolt question, i put upsetting for the bolt head and tapping for the thread. I didnt really like the theme of "rescue" either (with the ambulance, fire truck and helicopter winch), but ahh well, can't complain, all over now

 

[thehootman]

A (could be C, maybe there is special significance in the word "levels" in the question, not sure) EDIT: im thinking A more now, considering the fluid inside the vessel is gas, the pressures will so close together because the weight isnt substantial enough, so im thinking the readings will be the same

Dont forget, it also said "pressurised". Bearing in mind that a pressurised gas becomes denser, C will apply to this situation. Often, such containers are liquid "gas" (hence "liquid petroleum gas") and emerge from the container as gas, but are liquid in the container.

 

[Horyd]

yea i thought the pressurisation could increase density to such an extent, but i'd have to say im generally baffled by this question. It could go either way. I'm glad its just the one mark though

 

[aaronmott]

I just did a sine wave for the signal

I got 18KN resistant force (P=W/T, W=FxD)
I got 28.1m up the slope (from KE=1/2 x mv^2, equated to PE=mgh to find the height, then trig to find the distance)

The battery was 2 sets of 2 batteries in series, and the sets connected in parallel. So I think it's 12V

My Criteria were Cost, Weight, Environment, Reliability (mainetenance), availability of power (ie, solar doesn't work in the dark)

Arch bridge I guessed 50 degrees.
Ceramic insulator was for compression
Shear was 20KN?

for the car one, u forgot that Ke=Pe only half way up the hill, u have to double it to get the proper length,
ALL in all i thought the test was fairly easy, not as easy as the previous years though,

 

[aaronmott]

yea i thought the pressurisation could increase density to such an extent, but i'd have to say im generally baffled by this question. It could go either way. I'm glad its just the one mark though

i

If u use the equation on the formula sheet,
P= p+qgh, u can say that pressure increases as depth increases

 

[aaronmott]

i thought 2 batteries are connected in series each at the time, then 2 group are connected in parralel so the out put voltage is 12volts.

yeh man that is correct im pretty sure

 

[2syllables]

I just did a sine wave for the signal

I got 18KN resistant force (P=W/T, W=FxD)
I got 28.1m up the slope (from KE=1/2 x mv^2, equated to PE=mgh to find the height, then trig to find the distance)

The battery was 2 sets of 2 batteries in series, and the sets connected in parallel. So I think it's 12V

My Criteria were Cost, Weight, Environment, Reliability (mainetenance), availability of power (ie, solar doesn't work in the dark)

Arch bridge I guessed 50 degrees.
Ceramic insulator was for compression
Shear was 20KN?

YAH I GOT THE SAME ANSWER

- 18kn yes - i checked with my teacher he said its correct

- i got 28 too but im a bit unsure it sound to long

- LOL got the same criteria!

-Ceramic same

-Shear is not 20KN - BOS tricked people! (100% it's not 20) my answer is 10kn (im not sure)
it was a stupid question for multiple choice anyways

 

[Horyd]

im 100% it is 20kN

im not sure why you would double the distance, im pretty sure its just KE=PE

 

[thehootman]

for the car one, u forgot that Ke=Pe only half way up the hill, u have to double it to get the proper length,
ALL in all i thought the test was fairly easy, not as easy as the previous years though,

No you dont. When it is on level ground, all it has is kinetic energy. When it is stopped, it has converted all its kinetic energy into potential energy. Thus KE = PE.

 

[Omie Jay]

stress in my head = (Load of hsc)/(X-sect area of my head) = INFINITY


Yeah..that test was hard, but i answered everything and hopefully my crapped on answers get some marks.

 

[hkgirl]

i thought the exam was ok. wasn't too hard, i thought it was easier than past papers.
especially the engineering report part..i found that quite ok.

but the pressure & battery raped me hardcore ><

 

[AB639973]

18MJ is the total work done yes...but work is required to move the 5 tonne mass...so the 'resitive force' is the weight force of the truck minus 18kN