# HSC 2015 Engineering Studies Marathon (1 Viewer)

#### astroman

##### Well-Known Member
This thread is for the 2015 HSC Engineering Studies Students wishing to ask and receive answers to questions they may have. Since the engineering studies syllabus is broad and complex and the lack of knowledge available through textbooks as well as online is growing scarce, we should collaborate to work together to here to do our best to help out all the engineering studies students. Please try your best to answer the asked questions before asking another one.

I will start:

A boat of 1.85 Tonnes rests on a slip which is inclined at 18° to the horizontal, the coefficient of static friction between the slip-rails and the boat is 0.25. Determine the least force required in the winch cable to move the boat up the slip.

Last edited:

#### Squar3root

##### listening to tapes
Re: Engineering Studies Marathon

9910N

probably wrong but w/e

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

9910N

probably wrong but w/e

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

donno lel, i asked that question coz i needed to know, someone explains and then new question is posted.

#### Squar3root

##### listening to tapes
Re: Engineering Studies Marathon

donno lel, i asked that question coz i needed to know, someone explains and then new question is posted.
well what I did was

> free body diagram
> resolve forces
> algebra

got 9913 -> 9900 since the question is 2 sig fig

looks like 1st year physics

#### Shackleford

##### New Member
Re: Engineering Studies Marathon

Squar3root has the correct answer for that question.

perhaps if u want to take an extreme short cut, memorise this formula: mgsin(θ) + u(mgcos(θ)) = F, where F=force (N), m=mass (kg), u=coefficient of static friction, θ = angle of the incline (degrees) and g= acceleration due to gravity (ms^-2), to solve a problem like this. haha. solves any question like the one u posted, astroboy. use mgsin(θ) - u(mgcos(θ)) = F when friction supports you, i.e, when you just want to hold the boat on the plane to prevent it slipping down.

if u want to understand the underlying theories and stuff take squar3root's methods. they'd help you in the long run in helping you solve other similar problems without relying on formulas except for F=mg and f= uN etc.

tho there are some textbooks that give you an easier approach in solving these, like using the sine rule method to solve for the unknown force by using the equation where you base the math off the angle of limiting friction/angle of repose and stuff. if ur engineering teacher can't really explain it properly to ur standards, perhaps you should ask a physics teacher who would've experienced these types of problems before.

#### kalstar

##### swag
Re: Engineering Studies Marathon

well what I did was

> free body diagram
> resolve forces
> algebra

got 9913 -> 9900 since the question is 2 sig fig

looks like 1st year physics
na its just dynamics

#### kalstar

##### swag
Re: Engineering Studies Marathon

Squar3root has the correct answer for that question.

perhaps if u want to take an extreme short cut, memorise this formula: mgsin(θ) + u(mgcos(θ)) = F, where F=force (N), m=mass (kg), u=coefficient of static friction, θ = angle of the incline (degrees) and g= acceleration due to gravity (ms^-2), to solve a problem like this. haha. solves any question like the one u posted, astroboy. use mgsin(θ) - u(mgcos(θ)) = F when friction supports you, i.e, when you just want to hold the boat on the plane to prevent it slipping down.

if u want to understand the underlying theories and stuff take squar3root's methods. they'd help you in the long run in helping you solve other similar problems without relying on formulas except for F=mg and f= uN etc.

tho there are some textbooks that give you an easier approach in solving these, like using the sine rule method to solve for the unknown force by using the equation where you base the math off the angle of limiting friction/angle of repose and stuff. if ur engineering teacher can't really explain it properly to ur standards, perhaps you should ask a physics teacher who would've experienced these types of problems before.
you dont need any formulas tbh, its just resolving forces from a free body diagram lol. the only formula you would need is calculating friction

#### Squar3root

##### listening to tapes
Re: Engineering Studies Marathon

na its just dynamics
...

you dont need any formulas tbh, its just resolving forces from a free body diagram lol. the only formula you would need is calculating friction
yeah this.

it's easier to derive what you need rather than memorising

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

Does anyone have a summary of microstructure diagrams?

#### mandog97

##### Member
Re: Engineering Studies Marathon

Does anyone have a summary of microstructure diagrams?
This is what I need as well!!!!!!! Every single HSC exam has at least like 5+ marks on this and I don't even remember learning about it in the course.
Help!!!

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

This is what I need as well!!!!!!! Every single HSC exam has at least like 5+ marks on this and I don't even remember learning about it in the course.
Help!!!
I remember learning it but I never got a page of all the one's in the circle you can draw, if you search on google, you get one's that are all different.

#### keepLooking

##### Active Member
Re: Engineering Studies Marathon

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

awesome, do u know if these are the only one's in the course? I've seen some pretty crazy one's before.

#### keepLooking

##### Active Member
Re: Engineering Studies Marathon

awesome, do u know if these are the only one's in the course? I've seen some pretty crazy one's before.
Those are the ones in the OTEN notes, I haven't seen any 'crazy' ones yet.

#### astroman

##### Well-Known Member
Re: Engineering Studies Marathon

guys what personal and public transport do u think they are gonna talk about??

#### Apdo

##### New Member
Re: Engineering Studies Marathon

Uh, I got 10115.45N acting up the plane using F=μ*mgcosθ+mgsinθ

#### Shackleford

##### New Member
Re: Engineering Studies Marathon

you used g = 10m/s^2 instead of g = 9.8m/s^2

#### sendhelp

##### New Member
Re: Engineering Studies Marathon

you used g = 10m/s^2 instead of g = 9.8m/s^2
My teacher said using 10m/s^2 is perfectly fine in the HSC and I won't be marked down for it, is that true?