• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

How'd everyone go? (3 Viewers)

K

kleenextissues1

Guest
I cant even remember my answers to shit lol... but the (sqrt( 20^2 + 9^2) x f)/t sounds familiar
 
Joined
Sep 10, 2011
Messages
83
Gender
Undisclosed
HSC
2009
For the escalator, Power = W/t
W= change in PE + KE
So in this case W = PE
Hence Power = mgh/25 (25 seconds was the time.)

Weight was 115, height was 9, use 10 for g.

P = 115x9x10/25
=414

As for the Amps one I'm really not sure...

I think R was 800 ohms, 2 was what I used for V so,
2=Ix800
I = 2/800
=2.5x10-3 or 0.0025
x10-3 is milli, so 2.5mA I think...
Great minds think alike ;)
 

Twiglet

New Member
Joined
Oct 1, 2011
Messages
2
Gender
Undisclosed
HSC
2011
it was actually the MACRO-structure, it just wanted you to draw a cross section of a laminate. I did laminated glass= transparent polymer sheet sandwiched between sheets of annealed glass
 
Joined
Sep 10, 2011
Messages
83
Gender
Undisclosed
HSC
2009
I did the stuff they make the A380's fuselage out of: duraluminum with fibre glass behind it
 

xblacksheepx

New Member
Joined
Aug 13, 2011
Messages
18
Gender
Male
HSC
2011
but regardless of friction, wouldnt you have to work it out using the displacement from the starting point, and not just the height?
 

alen180sx

Member
Joined
Mar 30, 2010
Messages
43
Gender
Male
HSC
2011
What did you guys get for the reaction in the truss and the force in member x.
I got, reaction a= 14.1 force in x = 15.86(not 100%) but.
 

Skyge

New Member
Joined
Jun 30, 2011
Messages
11
Gender
Male
HSC
2011
Some random answers off the top of my head

For the one with escalator with 115kg on it, answer was 414W I think.
I got 40 something mm for the extension of the cable in the last question.
Question about the current in the circuit with the lightbulb I got 2.5mA.

Any of these answers ring a bell with anyone else?
Exactly what I got :D
 

taeyang

Member
Joined
May 6, 2011
Messages
335
Gender
Male
HSC
2011
Some random answers off the top of my head

For the one with escalator with 115kg on it, answer was 414W I think.
I got 40 something mm for the extension of the cable in the last question.
Question about the current in the circuit with the lightbulb I got 2.5mA.

Any of these answers ring a bell with anyone else?
That is what I got.
 

miniwaybzz

Member
Joined
Sep 14, 2010
Messages
85
Gender
Male
HSC
N/A
Jesus christ.... did anyone else fail hardcore at the drawings.. and ESPECIALLY the shear and bending moment diagrams? wtf was that? the force was like on a non given distance..
Macrostructure of laminates? are you fucking kidding me?
i had exact the same problems as you broo
 
Last edited:

jonathanli

New Member
Joined
May 26, 2010
Messages
6
Location
sydney
Gender
Male
HSC
2011
cant believe people r saying this exam was easy. fucken hardest engineering one ive ever come across...
did anyone get like 23 or so KN for member X. In compression as well?
The only maths that fucked me over was that bloody bicycle...
 

SnowTau

Member
Joined
Oct 11, 2011
Messages
73
Gender
Male
HSC
2011
For the voltage question I'm pretty sure its 20mA.

Voltage = 18V
Voltage drop(voltage lost in circuit) = 2V
So voltage = 16v

V= IR

16=I*800

I = 0.02A = 20mA

Similar to question18 in 2009 hsc exam
Ah I knew there was something to do with the voltage drop... However, the voltage went from 18 to 2, making the voltage drop 16. So from what you've written that still makes V = 2? Unless you just mistyped it or something.
 

SnowTau

Member
Joined
Oct 11, 2011
Messages
73
Gender
Male
HSC
2011
cant believe people r saying this exam was easy. fucken hardest engineering one ive ever come across...
did anyone get like 23 or so KN for member X. In compression as well?
The only maths that fucked me over was that bloody bicycle...
hmm for X...
I used joint A as to get rid of it and the 2/3 members i cut that i didn't want, leaving the 15KN force downwards and the 5KN wind from memory...
So from A, (4x15)+(1.42x5)-(Xx8sin(20))

So, X = (4x15)+(1.42x5)/8sin(20)

=24.5KN, and it was in compression.

Not sure if 1.42 was the right height for the wind, however.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 3)

Top