[Systems Engineering Teachers' Mailing List] Re: syseng Digest, Vol 29, Issue 5

Paul Jackson jackson at foxall.com.au
Mon Nov 5 15:21:45 EST 2007


On 5/11/07 9:38 AM, "syseng-request at edulists.com.au"
<syseng-request at edulists.com.au> wrote:

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> than "Re: Contents of syseng digest..."
> 
> 
> Today's Topics:
> 
>    1. RE: syseng Digest, Vol 29, Issue 2 (Roger Knight)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Mon, 5 Nov 2007 09:37:54 +1100
> From: "Roger Knight" <RKnight at stpats.vic.edu.au>
> Subject: [Systems Engineering Teachers' Mailing List] RE: syseng
> Digest, Vol 29, Issue 2
> To: "Systems and Engineering Teachers' Mailing List"
> <syseng at edulists.com.au>
> Message-ID:
> <EC8B0ED0F258A94498B697367C2913A2DE6EBD at Shalimar.stpats.vic.edu.au>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> G'day all. Yes, I also found the fuel cells one to be a bit out of left field.
> However, there is a reasonably good explanation of them given on page 33 of
> the Systems Engineering text, at least good enough to help answer the
> questions put by the practise exam.
> Hope this helps.
>  
> Cheers ... Roger
>  
>  
>  
> Roger Knight
> Technology Dept.
> St Patrick's College
> 1431 Sturt Street
> BALLARAT 3350 VIC
> 5331 1688
> rknight at stpats.vic.edu.au
> 
> ________________________________
> 
> From: syseng-bounces at edulists.com.au on behalf of Neville YOUNG
> Sent: Fri 11/2/2007 12:10 PM
> To: syseng at edulists.com.au
> Subject: RE: syseng Digest, Vol 29, Issue 2
> 
> 
> I think you guys are making things too hard. I believe that you are to assume
> that the diameter of the winch will not change, you can then work out how many
> metres/sec the wire is being that you can hauled in at. (Otherwise why would
> it have - show all working at the end)  If you attended the session at the
> DATTA (then the TEAV) the errors in the sample test were pointed out.
> Apparently a science teacher was responsible for the writing the exam. The
> surprising thing is the question on hydrogen fuel cells, how many people have
> covered that. I don't believe that it is identified as something that should
> be taught in the principles and concepts outline for the course.
>  
> Neville Young
> ________________________________
> 
> From: syseng-bounces at edulists.com.au on behalf of
> syseng-request at edulists.com.au
> Sent: Fri 2/11/2007 9:14 AM
> To: syseng at edulists.com.au
> Subject: syseng Digest, Vol 29, Issue 2
> 
> 
> 
> Send syseng mailing list submissions to
>         syseng at edulists.com.au
> 
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://www.edulists.com.au/mailman/listinfo/syseng
> or, via email, send a message with subject or body 'help' to
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> 
> You can reach the person managing the list at
>         syseng-owner at edulists.com.au
> 
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of syseng digest..."
> 
> 
> Today's Topics:
> 
>    1. RE: RE: sysengDigest,     Vol 28, Issue 12 Practice exam errors
>       (Powell, Warren S)
>    2. RE: RE: sysengDigest,     Vol 28, Issue 12 Practice exam errors
>       (Roger Knight)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Thu, 1 Nov 2007 20:30:24 +1100
> From: "Powell, Warren S" <powell.warren.s at edumail.vic.gov.au>
> Subject: RE: [Systems Engineering Teachers' Mailing List] RE:
>         sysengDigest,   Vol 28, Issue 12 Practice exam errors
> To: "Systems and Engineering Teachers' Mailing List"
>         <syseng at edulists.com.au>
> Message-ID:
>         <6AFA6726AC32AC47934F5F2E4E9D22A316788A at edusm01.education.vic.gov.au>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Since the drum spins on an axis the wire will be winched at a constant speed.
> Only the length of cable will change from layer to layer due to the changing
> diameter not the speed.
> 
> Regards,
> 
> Warren Powell
> Bayside Secondary College
> 
> 
> ________________________________
> 
> From: syseng-bounces at edulists.com.au on behalf of Robert Minato
> Sent: Tue 30-Oct-07 4:41 PM
> To: syseng at edulists.com.au
> Subject: Re: [Systems Engineering Teachers' Mailing List] RE: sysengDigest,
> Vol 28, Issue 12 Practice exam errors
> 
> 
> 
> As the spool rotates and reels the winch wire in, speed will be constant
> until the winch wire fills the first layer. When the wire starts the second
> layer, the circumference will be longer (radius now increased by thickness
> of wire). Speed will change each subsequent layer and torque will reduce.
> 
> The speed of the drum will not change; however, the speed at which the wire
> is hauled in (that's what the question is asking) will change for each
> layer.
> 
> PS. It's nice to see some discussion on this list. Keep it up.
> 
> 
> Rob
> --
> Robert Minato
> Technology Leader
> Catholic College Wodonga
> 1 Bowman Crt
> Wodonga 3690
> 02 6043 5546
> 
> 
> 
> On 30/10/07 2:05 PM, "Powell, Warren S" <powell.warren.s at edumail.vic.gov.au>
> wrote:
> 
>> Paul,
>> I also have notified them of the wrong answers and have had no reply.
>> In regard to Q12 the speed will not change. Only the diameter of the drum
>> will
>> change due to the cable coming and going. The drum is spinning on an axis
>> therefore the speed will not change. The torque might increase a little.
>> Hope this helps.
>> 
>> ________________________________
>> 
>> From: syseng-bounces at edulists.com.au on behalf of Barton, Paul S
>> Sent: Tue 10/30/2007 8:46 AM
>> To: syseng at edulists.com.au
>> Subject: RE: syseng Digest, Vol 28, Issue 12 Practice exam errors
>> 
>> 
>> I have asked Lorraine Tran and Kristen Allen for an answer sheet to the
>> practice exam questions over 4 months ago, as I also found problems with the
>> practice exam. I agree with your findings on questions 6,7,11, question 9
>> I'll
>> defer to your Knowledge. I also asked about question 5 (subjective), Question
>> 3 (formula should be Force= pressure X area), section B q1,I found I needed 3
>> pads and q12 the speed would be the minimum as the drum diameter increases so
>> would the speed. I have also stated the correct vr ratio should be driven
>> over
>> driver if we are to comply with industry standards.
>> 
>> Paul Barton
>> Technology teacher
>> Dromana Secondary College
>> 
>> ________________________________
>> 
>> From: syseng-bounces at edulists.com.au on behalf of
>> syseng-request at edulists.com.au
>> Sent: Mon 10/29/2007 12:00 PM
>> To: syseng at edulists.com.au
>> Subject: syseng Digest, Vol 28, Issue 12
>> 
>> 
>> 
>> Send syseng mailing list submissions to
>>         syseng at edulists.com.au
>> 
>> To subscribe or unsubscribe via the World Wide Web, visit
>>         http://www.edulists.com.au/mailman/listinfo/syseng
>> or, via email, send a message with subject or body 'help' to
>>         syseng-request at edulists.com.au
>> 
>> You can reach the person managing the list at
>>         syseng-owner at edulists.com.au
>> 
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of syseng digest..."
>> 
>> 
>> Today's Topics:
>> 
>>    1. Practice Exam errors (Robert Minato)
>> 
>> 
>> ----------------------------------------------------------------------
>> 
>> Message: 1
>> Date: Mon, 29 Oct 2007 09:43:06 +1000
>> From: Robert Minato <rminato at ccw.vic.edu.au>
>> Subject: [Systems Engineering Teachers' Mailing List] Practice Exam
>>         errors
>> To: "syseng at edulists.com.au" <syseng at edulists.com.au>
>> Message-ID: <7878124.6681193611395403.JavaMail.root at localhost>
>> Content-Type: text/plain; charset=US-ASCII
>> 
>> Had a look at the new practice exam on the vcaa website. There are a few
>> problems with it:
>> 
>> Section A
>> Q6. Symbol for a voltage reg is not on the vcaa symbols list. Responses A, B
>> and D all represent another component, so by default, Response C is left
>> which must be the correct answer.
>> Q7. 120 and 600 Ohm in parallel gives 100 Ohms. 12V/100Ohms = 120 mA. No
>> correct response.
>> Q11. Brown Green Yellow resistor is 150 kOhms. No correct response.
>> 
>> Section B
>> Q9. The motor will only ever rotate in one direction. The back emf diode
>> will be forward biased in one switch position effectively shorting across
>> the motor. [Depending on the current supply and diode rating, the diode may
>> burn-out, in which case the motor will then work in the second direction.
>> Back emf diodes normally used when other components (eg transistor) are in
>> circuit to prevent damage.]
>> 
>> Formula sheet
>> The resistor colour code needs a multiplier column. Unless a great deal of
>> time has been spent with the code, most students would nave some trouble
>> with the multiplier. Probably explains the confusion with Section A Q11.
>> 
>> Rob
>> 
>> 
>> --
>> Robert Minato
>> Technology Leader
>> Catholic College Wodonga
>> 1 Bowman Crt
>> Wodonga 3690
>> 02 6043 5546
>> 
>> 
>> 
>> 
>> ------------------------------
>> 
>> _______________________________________________
>> syseng mailing list
>> syseng at edulists.com.au
>> http://www.edulists.com.au/mailman/listinfo/syseng
>> 
>> 
>> End of syseng Digest, Vol 28, Issue 12
>> **************************************
>> 
>> 
>> 
>> Important - This email and any attachments may be confidential. If received
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>> error, please contact us and delete all copies. Before opening or using
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>> or consequence, whether caused by the negligence of the sender or not,
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>> liability is limited to resupplying any affected attachments. Any
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>> not necessarily those of the Department of Education and Early Childhood
>> Development.
>> _______________________________________________
>> http://www.edulists.com.au <http://www.edulists.com.au/>
>> <http://www.edulists.com.au/>  - FAQ, resources, subscribe, unsubscribe
>> Systems and Technology Mailing List kindly supported by
>> http://www.vcaa.vic.edu.au/vce/studies/systemseng/systemsengindex.html -
>> Victorian Curriculum and Assessment Authority and
>> TEAV - Technology Education Association of Victoria
> 
> 
> 
> _______________________________________________
> http://www.edulists.com.au <http://www.edulists.com.au/>
> <http://www.edulists.com.au/>  - FAQ, resources, subscribe, unsubscribe
> Systems and Technology Mailing List kindly supported by
> http://www.vcaa.vic.edu.au/vce/studies/systemseng/systemsengindex.html -
> Victorian Curriculum and Assessment Authority and
> TEAV - Technology Education Association of Victoria
> 
> 
> 
> Important - This email and any attachments may be confidential. If received in
> error, please contact us and delete all copies. Before opening or using
> attachments check them for viruses and defects. Regardless of any loss, damage
> or consequence, whether caused by the negligence of the sender or not,
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> ------------------------------
> 
> Message: 2
> Date: Fri, 2 Nov 2007 09:13:31 +1100
> From: "Roger Knight" <RKnight at stpats.vic.edu.au>
> Subject: RE: [Systems Engineering Teachers' Mailing List] RE:
>         sysengDigest,   Vol 28, Issue 12 Practice exam errors
> To: "Systems and Engineering Teachers' Mailing List"
>         <syseng at edulists.com.au>
> Message-ID:
>         <EC8B0ED0F258A94498B697367C2913A2DE6EB9 at Shalimar.stpats.vic.edu.au>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> G'day all. I was just wondering how do we know when the winch wire fills the
> first layer without knowing the width of the drum? Could it be that the
> examiners are just looking for an approximate value based on the known values?
> 
> Cheers ... Roger
> 
> ________________________________
> 
> From: syseng-bounces at edulists.com.au on behalf of Powell, Warren S
> Sent: Thu 11/1/2007 8:30 PM
> To: Systems and Engineering Teachers' Mailing List
> Subject: RE: [Systems Engineering Teachers' Mailing List] RE: sysengDigest,
> Vol 28, Issue 12 Practice exam errors
> 
> 
> Since the drum spins on an axis the wire will be winched at a constant speed.
> Only the length of cable will change from layer to layer due to the changing
> diameter not the speed.
> 
> Regards,
> 
> Warren Powell
> Bayside Secondary College
> 
> 
> ________________________________
> 
> From: syseng-bounces at edulists.com.au on behalf of Robert Minato
> Sent: Tue 30-Oct-07 4:41 PM
> To: syseng at edulists.com.au
> Subject: Re: [Systems Engineering Teachers' Mailing List] RE: sysengDigest,
> Vol 28, Issue 12 Practice exam errors
> 
> 
> 
> As the spool rotates and reels the winch wire in, speed will be constant
> until the winch wire fills the first layer. When the wire starts the second
> layer, the circumference will be longer (radius now increased by thickness
> of wire). Speed will change each subsequent layer and torque will reduce.
> 
> The speed of the drum will not change; however, the speed at which the wire
> is hauled in (that's what the question is asking) will change for each
> layer.
> 
> PS. It's nice to see some discussion on this list. Keep it up.
> 
> 
> Rob
> --
> Robert Minato
> Technology Leader
> Catholic College Wodonga
> 1 Bowman Crt
> Wodonga 3690
> 02 6043 5546
> 
> 
> 
> On 30/10/07 2:05 PM, "Powell, Warren S" <powell.warren.s at edumail.vic.gov.au>
> wrote:
> 
>> Paul,
>> I also have notified them of the wrong answers and have had no reply.
>> In regard to Q12 the speed will not change. Only the diameter of the drum
>> will
>> change due to the cable coming and going. The drum is spinning on an axis
>> therefore the speed will not change. The torque might increase a little.
>> Hope this helps.
>> 
>> ________________________________
>> 
>> From: syseng-bounces at edulists.com.au on behalf of Barton, Paul S
>> Sent: Tue 10/30/2007 8:46 AM
>> To: syseng at edulists.com.au
>> Subject: RE: syseng Digest, Vol 28, Issue 12 Practice exam errors
>> 
>> 
>> I have asked Lorraine Tran and Kristen Allen for an answer sheet to the
>> practice exam questions over 4 months ago, as I also found problems with the
>> practice exam. I agree with your findings on questions 6,7,11, question 9
>> I'll
>> defer to your Knowledge. I also asked about question 5 (subjective), Question
>> 3 (formula should be Force= pressure X area), section B q1,I found I needed 3
>> pads and q12 the speed would be the minimum as the drum diameter increases so
>> would the speed. I have also stated the correct vr ratio should be driven
>> over
>> driver if we are to comply with industry standards.
>> 
>> Paul Barton
>> Technology teacher
>> Dromana Secondary College
>> 
>> ________________________________
>> 
>> From: syseng-bounces at edulists.com.au on behalf of
>> syseng-request at edulists.com.au
>> Sent: Mon 10/29/2007 12:00 PM
>> To: syseng at edulists.com.au
>> Subject: syseng Digest, Vol 28, Issue 12
>> 
>> 
>> 
>> Send syseng mailing list submissions to
>>         syseng at edulists.com.au
>> 
>> To subscribe or unsubscribe via the World Wide Web, visit
>>         http://www.edulists.com.au/mailman/listinfo/syseng
>> or, via email, send a message with subject or body 'help' to
>>         syseng-request at edulists.com.au
>> 
>> You can reach the person managing the list at
>>         syseng-owner at edulists.com.au
>> 
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of syseng digest..."
>> 
>> 
>> Today's Topics:
>> 
>>    1. Practice Exam errors (Robert Minato)
>> 
>> 
>> ----------------------------------------------------------------------
>> 
>> Message: 1
>> Date: Mon, 29 Oct 2007 09:43:06 +1000
>> From: Robert Minato <rminato at ccw.vic.edu.au>
>> Subject: [Systems Engineering Teachers' Mailing List] Practice Exam
>>         errors
>> To: "syseng at edulists.com.au" <syseng at edulists.com.au>
>> Message-ID: <7878124.6681193611395403.JavaMail.root at localhost>
>> Content-Type: text/plain; charset=US-ASCII
>> 
>> Had a look at the new practice exam on the vcaa website. There are a few
>> problems with it:
>> 
>> Section A
>> Q6. Symbol for a voltage reg is not on the vcaa symbols list. Responses A, B
>> and D all represent another component, so by default, Response C is left
>> which must be the correct answer.
>> Q7. 120 and 600 Ohm in parallel gives 100 Ohms. 12V/100Ohms = 120 mA. No
>> correct response.
>> Q11. Brown Green Yellow resistor is 150 kOhms. No correct response.
>> 
>> Section B
>> Q9. The motor will only ever rotate in one direction. The back emf diode
>> will be forward biased in one switch position effectively shorting across
>> the motor. [Depending on the current supply and diode rating, the diode may
>> burn-out, in which case the motor will then work in the second direction.
>> Back emf diodes normally used when other components (eg transistor) are in
>> circuit to prevent damage.]
>> 
>> Formula sheet
>> The resistor colour code needs a multiplier column. Unless a great deal of
>> time has been spent with the code, most students would nave some trouble
>> with the multiplier. Probably explains the confusion with Section A Q11.
>> 
>> Rob
>> 
>> 
>> --
>> Robert Minato
>> Technology Leader
>> Catholic College Wodonga
>> 1 Bowman Crt
>> Wodonga 3690
>> 02 6043 5546
>> 
>> 
>> 
>> 
>> ------------------------------
>> 
>> _______________________________________________
>> syseng mailing list
>> syseng at edulists.com.au
>> http://www.edulists.com.au/mailman/listinfo/syseng
>> 
>> 
>> End of syseng Digest, Vol 28, Issue 12
>> **************************************
>> 
>> 
>> 
>> Important - This email and any attachments may be confidential. If received
>> in
>> error, please contact us and delete all copies. Before opening or using
>> attachments check them for viruses and defects. Regardless of any loss,
>> damage
>> or consequence, whether caused by the negligence of the sender or not,
>> resulting directly or indirectly from the use of any attached files our
>> liability is limited to resupplying any affected attachments. Any
>> representations or opinions expressed are those of the individual sender, and
>> not necessarily those of the Department of Education and Early Childhood
>> Development.
>> _______________________________________________
>> http://www.edulists.com.au <http://www.edulists.com.au/>
>> <http://www.edulists.com.au/>  - FAQ, resources, subscribe, unsubscribe
>> Systems and Technology Mailing List kindly supported by
>> http://www.vcaa.vic.edu.au/vce/studies/systemseng/systemsengindex.html -
>> Victorian Curriculum and Assessment Authority and
>> TEAV - Technology Education Association of Victoria
> 
> 
> 
> _______________________________________________
> http://www.edulists.com.au <http://www.edulists.com.au/>
> <http://www.edulists.com.au/>  - FAQ, resources, subscribe, unsubscribe
> Systems and Technology Mailing List kindly supported by
> http://www.vcaa.vic.edu.au/vce/studies/systemseng/systemsengindex.html -
> Victorian Curriculum and Assessment Authority and
> TEAV - Technology Education Association of Victoria
> 
> 
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> ------------------------------
> 
> _______________________________________________
> syseng mailing list
> syseng at edulists.com.au
> http://www.edulists.com.au/mailman/listinfo/syseng
> 
> 
> End of syseng Digest, Vol 29, Issue 2
> *************************************
> 
> 
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> ------------------------------
> 
> _______________________________________________
> syseng mailing list
> syseng at edulists.com.au
> http://www.edulists.com.au/mailman/listinfo/syseng
> 
> 
> End of syseng Digest, Vol 29, Issue 5
> *************************************
> 
>From Paul Jackson. Lilydale High. Here is some more, if you haven't seen it.
The Fuel Cell description in the proof copy of Systems Engineering is
incorrect.  The Anode is NEGATIVE and the cathode is POSITIVE. Not the
reverse as described. ( Maybe it's been fixed, I only have a proof copy.)

Q3 is ambiguous and would need to STATED as hydraulics.  If so, the correct
answer is B (10N).  Can be looked at differently to give an answer of
2.5N.(D)

The  correct answer to Q7 is 0.12A or 120mA.

The correct answer to Q11 is 150K

Question 9 will not work with the addition of a switch unless the diode is
removed!

Section B Q1 The board can be completed with THREE missing tracks and two
pads.

Hope this is helpful.




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