Engineering Marathon (2 Viewers)

[tashisthebest]

and question 14, a, ii
two lifting cabels, one on each side, are required to lift a 400kg door. the steel lifting cabels are each 5m long and each has a cross sectional area of 27mm^2. the modulas of elasticity of the steel in the cabels is 230GPa.

calculate the extension of each cable.

*i got 3.2mm each cable*

can someone plaese do these questions and tell me what they got?
include all working so we know how u got what u got[/quote]

i divided the force by 2 casue they are 2 cables

e= LF
EA
e= 5 x 2000
(230*10^9 x 27*10^-6)
e= 1.61*10^-3 m
e= 0.0016mm

if im rong let me know.

 

[jetwillnotfail]

Define the responsibilities of the aeronautical engineer and also describe the nature and range of work done in this profession. /4

 

[untouchablecuz]

wish i did engineering studies :mad1:

 

[clintmyster]

wish i did engineering studies :mad1:

seems pretty interesting aye. I read like the first page of questions and it seems its a mixture of chem/phys at times.

 

[Kaos1]

an aeronautical engineer is responsibile for making sure the safety around an airfield / workshop is paramount at all times. he also needs to make sure that all aircraft re up to required aviation authority specifications; ensuring regular inspections of aircraft, all staff traind to the necessary level, and any minor or major alterations to any aircraft are pre approved by him before applied to the aircraft. also, if there is a crash, an aeronautical engineer is needed to help with the investigation, and lend asistance to and reasioning behind a fault in the aircrft.

an aeronautical engineer can also play a big role in the design and manufacure of a new aircraft


what is 'velocity ratio' and how does it apply to levers and pulleys?

 

[yz125]

what is 'velocity ratio' and how does it apply to levers and pulleys?

Velocity ratio = distance effort/distance load.

In levers, the closer the effort is to the fulcrum, the greater the distance the load will be. For pulleys, the distant effort is greater then the ditance load e.g. if there are 2 pulleys then for every 1m of effort, the load will move 1/2 a metre, hence the velocity ratio is 2.

Question: Explain how an analogue signal is converted into a digital signal.

 

[Kaos1]

i an explain it in a drawing... but its kinda hard to explain in writing. can someone else try?

 

[bossleymaths]

i would talk about sampling, and how the different rates applied allows for the conversion of analogue signal to a binary digital signal

 

[bossleymaths]

QUESTION: TELECOMM.

name the three different cables. explain each cables function. provide an example of their use in the real world.

 

[00iCon]

QUESTION: TELECOMM.

name the three different cables. explain each cables function. provide an example of their use in the real world.

Coaxial. A copper core with thick polymer insulation and a metal shield and more insulation. This is used for long to medium distance communiaction such as cable television and cable internet.

Twisted Pairs. Two or more insulated copper strands twisted around each other. This is used for short distaces because it is affected by attenuation and noise. For example, ethernet cables used in schools for the network.

Fibre optic. A thin glass core surrounded by material and created in a complex process. It is used for long distance communication due to its low attenuation and is unaffected by electromagnetic disturbances. An example is undresea internet cables.

 

[00iCon]

Describe 3 structural development in civil structures (preferably bridges) and 3 materials developments.

 

[qwertyuiop1234]

Question: Explain how an analogue signal is converted into a digital signal.

The analogue signal is sampled at at least twice the maximum frequency and the quantised (put into either 0's or 1's depending on what is closer) and OMG!! its digital!

 

[arman]

Describe 3 structural development in civil structures (preferably bridges) and 3 materials developments.

Structural: 1: development of truss rather than solid beam bridge - reduced weight with increased strength
2: use of cables in cable-stayed and suspension bridges - also reduced weight
3: pre-stressed and post-stressed concrete

Materials: 1: re-inforced concrete - much stronger and increases tensile strength - composite material
2: high tensile steel - for use in multi-strand cables
3:

 

[arman]

Question: Describe sand casting

 

[qwertyuiop1234]

Describe 3 structural development in civil structures (preferably bridges) and 3 materials developments.

I hate these sort of questions but i'll give it a go...
Material 1. The finding of concrete and its uses as a compressive load taker.
2. Ability to reinforce concrete using deformed steel bars giving it good tension properties.
3. High tensile steel cables made of many smaller cables wrapped around each other to give flexibility and superior strength.

Structural 1. Discovery of the truss system and how it reduces mass and increases overall strength due to the greater second moment of area.
2. The arch, its ability to take compressive loads and the realisation that it can be both above and below the actual bridge.
3. Suspension bridges and the massive distances they can span.

Q. How are ceramics shaped?

 

[qwertyuiop1234]

and question 14, a, ii
two lifting cabels, one on each side, are required to lift a 400kg door. the steel lifting cabels are each 5m long and each has a cross sectional area of 27mm^2. the modulas of elasticity of the steel in the cabels is 230GPa.

calculate the extension of each cable.

*i got 3.2mm each cable*

can someone plaese do these questions and tell me what they got?
include all working so we know how u got what u got

i divided the force by 2 casue they are 2 cables

e= LF
EA
e= 5 x 2000
(230*10^9 x 27*10^-6)
e= 1.61*10^-3 m
e= 0.0016mm

if im rong let me know.[/QUOTE]

I think you got the area wrong, its (pi x .027^2)/4
OR pi x .0135^2
then you get
e = 5 x 2000
230*10^9 x 5.73*10^-4
e= .0759mm

 

[arman]

Q. How are ceramics shaped?

by hand?
rolling?
i never considered this question b4

 

[bossleymaths]

by hand?
rolling?
i never considered this question b4

rolling?? i dont think so, seems to me that it will break and cause heaps of stresses. but by hand would be a reasonable answer for me depending on what type of ceramic, cuz theres glass as well hmmm..

will that leads me to this question. HOW is glass formed and what is special about toughened glass in the way it was formed?

 

[Kaos1]

depending on the application, ceramics can be shaped a number of ways. by hand allows for the variety and flexibility of the crafter, rolling increases strength, casting, mass produced (product line), the possibilities are endless depending on the application.

an induction motor is chosen for a door lifing mechanism.

outline TWO reasons for this choice of electric motor

 

[qwertyuiop1234]

rolling?? i dont think so, seems to me that it will break and cause heaps of stresses. but by hand would be a reasonable answer for me depending on what type of ceramic, cuz theres glass as well hmmm..

will that leads me to this question. HOW is glass formed and what is special about toughened glass in the way it was formed?

I think ceramics are mostly made to shape when they are clay and then fired.

Toughened glass is formed by heating the glass and then blasting the outsides of it with cooled air which places the outside in compression and the inside in tension so any force needs to first overcome the compressive force before the glass will break. When toughened glass breaks it breaks into lots of tiny little pieces that have rounded edges so they won't hurt anyone. Mostly used in the side windows of vehicles.