MECHANICS IS TORTURE. -___-

[ParanoidAleveler]

Some one PLEASE tell me how to do this part! I've spent like 2 hours on it already

http://www.xtremepapers.me/CIE/International A And AS Level/9709 - Mathematics/9709_w06_qp_5.pdf


It's question 6 :O:

 

[ParanoidAleveler]

Please help guys! i really cant solve it!

 

[fluffycloud]

You are taking M2?
whaaaaaa....enjoyy

 

[thabomanqoba]

I thought i was the only one, i tried the exact number and didnot find it nice, but it was a mistake on the question itself that cambridge made. just like the mistake they made on coeffient of friction in may june 2011 M1 ie it was more than 1.

 

[ParanoidAleveler]

are u serious?! =O
WTF?! no but how do u know it was CIE's mistake?

 

[abuhantash]

M2 Its terrible .. I hope it goes like P3 did =[

 

[SarahKotb]

No it is not a mistake on the paper.
My teacher did it with us but it wasnt easy.
I will explain it but I hope u understand it.
first find the centre of mass from the origin
this is equal to 10/3pie
draw a line from the origin through the COM.
drop a vertical line from the origin thus the line u
drew through the COM makes an angle alpha with the vertical
cos alpha = 4/5 sin alpha = 3/5 from the big triangle
use this to find the horizontal distance from the COM to the vertical
this is equal to 2/pie
now draw a horizontal line from point A to the same vertical line u drew previously
this line makes an angle alpha the same as the previous one with AC
AO =2.5
SO the horizontal distance = 2.5cos alpha =2
therefore, the distance from AB to the COM is 2+2/pie
i hope u ynderstand something from all this
if u dont understand give me your email and i will send
u an attachment with the diagram

 

[abuhantash]

lol .. weird .. I got it quiet quickly while solving.. hope it goes like this in the exam =]

 

[kingmanu]

people do we need to know vectors in mechanics

 

[abuhantash]

no we dont o.0 just integration

 

[ParanoidAleveler]

No it is not a mistake on the paper.
My teacher did it with us but it wasnt easy.
I will explain it but I hope u understand it.
first find the centre of mass from the origin
this is equal to 10/3pie
draw a line from the origin through the COM.
drop a vertical line from the origin thus the line u
drew through the COM makes an angle alpha with the vertical
cos alpha = 4/5 sin alpha = 3/5 from the big triangle
use this to find the horizontal distance from the COM to the vertical
this is equal to 2/pie
now draw a horizontal line from point A to the same vertical line u drew previously
this line makes an angle alpha the same as the previous one with AC
AO =2.5
SO the horizontal distance = 2.5cos alpha =2
therefore, the distance from AB to the COM is 2+2/pie
i hope u ynderstand something from all this
if u dont understand give me your email and i will send
u an attachment with the diagram

i get it now!
I can thank you a MILLION times for this!

Good luck!

 

[kingmanu]

how was the mechanics exam

 

[MasterOfPuppets]

I thought i was the only one, i tried the exact number and didnot find it nice, but it was a mistake on the question itself that cambridge made. just like the mistake they made on coeffient of friction in may june 2011 M1 ie it was more than 1.

I just want to clarify something. The coefficient of friction can in fact exceed 1, but that's rare. Not impossible, not wrong.