• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

General Thoughts: Engineering Studies (1 Viewer)

LlamaBoi

Member
Joined
Oct 23, 2012
Messages
31
Gender
Male
HSC
2012
For the bus question how did everybody do it?
I equated the work done to the kinetic energy, i.e. Fd = 0.5mv^2 and I got a reasonable answer of 15 km/h or something...not anywhere near 300's haha
 

mashups

New Member
Joined
Aug 7, 2012
Messages
8
Gender
Undisclosed
HSC
2012
the coating of the cables is done through extrusion. but i agree this test was extremely difficult. i didnt even attempt to "finish off" the drawing of the aeroplane door hinge. that was bs
 

machine2035

Member
Joined
Mar 21, 2012
Messages
65
Gender
Male
HSC
N/A
the coating of the cables is done through extrusion. but i agree this test was extremely difficult. i didnt even attempt to "finish off" the drawing of the aeroplane door hinge. that was bs
holy crap what a guess i mate.. I remembered seeing something about extrusion so I took a punt and looks like it payed off.

My hinge looked more like one that had been recovered after a plane crash.
 

Heydosaurus

Member
Joined
Feb 28, 2011
Messages
55
Location
Maitland, NSW
Gender
Male
HSC
2012
Mmm yes, you are right if you sum the vertical force you get 17.3 as vertical, however I also took moments from the right hand side reaction and got 17.3.. I think the angle support confused the f out of me
Wouldn't that be due to the fact that when you take a moment from a roller, you only end up with the vertical forces?
 

laser6628

New Member
Joined
Nov 12, 2011
Messages
24
Gender
Undisclosed
HSC
N/A
i did
PE=KE
mgh=.5mv^2
rearranged to
v=(2gh)^.5

where h=700sin40
 

machine2035

Member
Joined
Mar 21, 2012
Messages
65
Gender
Male
HSC
N/A
Wouldn't that be due to the fact that when you take a moment from a roller, you only end up with the vertical forces?
I thought it's just that rollers always have the reaction perpendicular to the horizontal. I wasn't aware that if you take moments about a roller (or from it) that you only find vertical forces.

i did
PE=KE
mgh=.5mv^2
rearranged to
v=(2gh)^.5

where h=700sin40
Yep, I did the same.
 

Life4Never

New Member
Joined
Feb 25, 2011
Messages
23
Gender
Male
HSC
2012
Wouldn't that be due to the fact that when you take a moment from a roller, you only end up with the vertical forces?
Moments can only find the vertical components. To find the NET force on a pin joint you need to consider forces horizontal and vertical. Don't have to worry about this on a roller as there is only force perpendicular to the plane its on.

What I did was use moments to find reaction at the roller support and then used sum of forces horizontal and vertical to get the pin joint reaction.
 

Bnr

New Member
Joined
Mar 28, 2012
Messages
8
Gender
Male
HSC
2012
Moments can only find the vertical components. To find the NET force on a pin joint you need to consider forces horizontal and vertical. Don't have to worry about this on a roller as there is only force perpendicular to the plane its on.

What I did was use moments to find reaction at the roller support and then used sum of forces horizontal and vertical to get the pin joint reaction.
what did you get for CE or whatever they specified? I got something like 543N
 

Heydosaurus

Member
Joined
Feb 28, 2011
Messages
55
Location
Maitland, NSW
Gender
Male
HSC
2012
Moments can only find the vertical components. To find the NET force on a pin joint you need to consider forces horizontal and vertical. Don't have to worry about this on a roller as there is only force perpendicular to the plane its on.

What I did was use moments to find reaction at the roller support and then used sum of forces horizontal and vertical to get the pin joint reaction.
Yeah, that's right. Anyways, I ended up with a resultant force of 22 kN at 50-ish degrees, so hopefully the result ends up being satisfactory. =P

Also, I ended up with 9 kN (8.9 rounded up) for CE, too. Compression or tension?
 

harudew

New Member
Joined
Mar 28, 2012
Messages
8
Gender
Male
HSC
2012
holy shit this is amazing. I have been shitting bricks all afternoon preparing to not get into uni, thankfully it truly was a bung hole of an exam.
 

machine2035

Member
Joined
Mar 21, 2012
Messages
65
Gender
Male
HSC
N/A
Yeah, that's right. Anyways, I ended up with a resultant force of 22 kN at 50-ish degrees, so hopefully the result ends up being satisfactory. =P

Also, I ended up with 9 kN (8.9 rounded up) for CE, too. Compression or tension?
I think I had tension

I am so pissed I put down 17.3kN.. I think i originally put down 22.1 or whatever was and my force triangle is probally still there on the page.
 
Last edited:

Life4Never

New Member
Joined
Feb 25, 2011
Messages
23
Gender
Male
HSC
2012
Yeah, that's right. Anyways, I ended up with a resultant force of 22 kN at 50-ish degrees, so hopefully the result ends up being satisfactory. =P

Also, I ended up with 9 kN (8.9 rounded up) for CE, too. Compression or tension?
Yes it was 9 kN under compression.

Truss was pushing out.
 
Last edited:

Capt Rifle

Member
Joined
Jul 17, 2012
Messages
399
Gender
Male
HSC
2013
i chose engineering studies in year 10 for prelim and it didnt even run at my school :( teacher left apparently
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top