Mathematics: Post your doubts here!

[Mayedah]

Because it says, 'at the instant when the string breaks', that means as P has a greater weight, it will fall towards the ground (downwards) and Q will travel upwards. therefore the velocities will have opposite directions. as P travelling down with for eg +V nd Q upwards with -V...or vice versa.
Jazak Allah khair. Remember me in ur prayers. And did u get it?!

I think its not possible that after the string break Q will travel up...the sign is maybe because Q was first travelling up and now down and as velocity is a vector so it changes sign !
Thanks anyways

 

[AlishaK]

I think its not possible that after the string break Q will travel up...the sign is maybe because Q was first travelling up and now down and as velocity is a vector so it changes sign !
Thanks anyways

Firstly, the sign aint specified in the mark scheme and yeah What i said was right...ya know how...when initially the string breaks, p is heavier so q will travel a distance upward and as P hits the ground, then Q will fall downwards. As the question later says 'Q reaches the ground 0.8 secs later than P'...if both were to fall to the ground at the instant the string breaks they both would reach the ground at the same time as they are the same height above the ground...Think logically...
And Anytime!

 

[GorgeousEyes]

November 2012 v.43 no.i ii

 

[ahmed abdulla]

For particle P:

u=20, a=-10,
s=ut+0.5at^2
s=20t+(0.5 x -10 x t^2)
s=20t - 0.5t^2

For Particle Q:
u=25, a=-10, time=t-4
s=25(t-4) - 0.5(t-4)^2
After simplifying you get
s=29t + 10.8 - 5t^2

Now equate both the distances :
20t-0.5t^2 = 29t + 10.8 -5t^2
After solving this you'll get t=1.2

For Particle P:
v=u+at
v=20+(-10 x 1.2) = 8m/s

For Particle Q:
v=25-10(t-0.4)
v=25-10(1.2-0.4) = 17m/s

I hope you got it

thanks .... can u plz tell me about no.7 WHY we equated it with 0 for accelaration ?
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w10_qp_42.pdf

 

[Anika Raisa]

HELP NEEDED!!! P3!CIE A LEVEL! Wud be grateful!

The attatchment has both the markscheme n d question! Please help by answering in detail! I get the sum screwed up everytym!
Thank u!

 

[Jiyad Ahsan]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_41.pdf
Q4(ii), it says in the ms that direction changes at 12 secs.. how do you calc that? i cant seem to get it

 

[Khalid Mohammed Okiely]

Can someone please explain how question 8(full) is solved? Which steps must be included etc.

This paper

 

[AlishaK]

Can someone please explain how question 8(full) is solved? Which steps must be included etc.

This paper

I would but I got mechanics tomorrow. If you can wait then I shall explain you by tomorrow In sha Allah!

 

[Khalid Mohammed Okiely]

I would but I got mechanics tomorrow. If you can wait then I shall explain you by tomorrow In sha Allah!

No problem, really. I have the exam 8 days from now, so tyt

Thank you and super good luck insha'a Allah

 

[Silent Hunter]

I would but I got mechanics tomorrow. If you can wait then I shall explain you by tomorrow In sha Allah!

hey ..... one thing : a general question :

if it says that two particles re on inclined plane with one moving up and the other moving down , finding an expression for distance between them if one is released 2 second later ? so in this case the t (for the one released 2 seconds later) = 0.2 + t ?

JazakAllah

 

[haha101]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_41.pdf

Q 7 how did they resolve the forces ?

 

[Esme]

HELP NEEDED!!! P3!CIE A LEVEL! Wud be grateful!

The attatchment has both the markscheme n d question! Please help by answering in detail! I get the sum screwed up everytym!
Thank u!

Will try this one after mechanics...though it looks like a simple differential equations question

 

[Esme]

hey ..... one thing : a general question :

if it says that two particles re on inclined plane with one moving up and the other moving down , finding an expression for distance between them if one is released 2 second later ? so in this case the t (for the one released 2 seconds later) = 0.2 + t ?

JazakAllah

This question rings a bell, which year ?
btw I think time should be t-2.

 

[AlishaK]

hey ..... one thing : a general question :

if it says that two particles re on inclined plane with one moving up and the other moving down , finding an expression for distance between them if one is released 2 second later ? so in this case the t (for the one released 2 seconds later) = 0.2 + t ?

JazakAllah

I'm not really sure but wouldn't it be t-0.2 cause for eg: if those two particles r battery cars A and B, where A travels down and B up, So if B is released from rest nd let go, so after 0.2s A is released and travels downward. Hence, at any time ts it will be final value (t) - initial value (0.2s)...
Don't know if it makes sense to you!
Jazak Allah Khair!

 

[haha101]

first of all find two instances of time when velocity is zero . ( when direction is changed velocity becomes 0 )
you will get t=0 n t=12 . ( use the equation given in the Q and put 0 in place of v )

Hope it helped . please pray for me

 

[haha101]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_41.pdf

Q 7 how did they resolve the forces ?

anyone Esme

 

[Silent Hunter]

This question rings a bell, which year ?
btw I think time should be t-2.

I'm not really sure but wouldn't it be t-0.2 cause for eg: if those two particles r battery cars A and B, where A travels down and B up, So if B is released from rest nd let go, so after 0.2s A is released and travels downward. Hence, at any time ts it will be final value (t) - initial value (0.2s)...
Don't know if it makes sense to you!
Jazak Allah Khair!

cant remember the paper.... did this few weeks ago so cant recall..... just recalled the scenario
so confirm it should be t-2 ? these type are so confusing :\ anybody recalls a paper similar to this?

 

[AlishaK]

cant remember the paper.... did this few weeks ago so cant recall..... just recalled the scenario
so confirm it should be t-2 ? these type are so confusing :\ anybody recalls a paper similar to this?

You asked me something like this before I guess. Anyhow, I'd preferably write that. It's up to you.
Cheerio!

 

[Silent Hunter]

You asked me something like this before I guess. Anyhow, I'd preferably write that. It's up to you.
Cheerio!

thanks alot

 

[GorgeousEyes]

Nov012 v.42 no4 :S