Mathematics: Post your doubts here!

[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

 

[GorgeousEyes]

Is a=gsintheta a rule ??

 

[Esme]

anyone Esme

I got this one but I don't how to explain it.. sorry.. it's a bit complicated!

 

[Esme]

Is a=gsintheta a rule ??

No it depends on the question...

 

[Esme]

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

i found dv/dt first i.e. the acceleration.. and because the question says speed is increasing, so dv/dt > 0
So you'll the get the two values of T for which the speed is increasing, or for which the acceleration is positive however you want to see it. But just understand the question..

 

[ZainH]

Nov012 v.42 no4 :S

They've given you one of the forces in the y-direction already, 75N . Since they mentioned positive y-direction that means upwards. Anything down will be taking as negative so you'll have to change the sign later.

To find the other two forces use Pythagoras because you have the x-direction and the resultant so you'll get one force as.
68^2-60^2 = √1024 = -32N
Change it to positive = 32N

And the other as
100^2-96^2 = √784 = -28
Change it to positive = 28N

Hope you got it x)

 

[Esme]

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?

Yeah t-2 it is just imagine what the question is saying in your head and you'll get it

 

[GorgeousEyes]

They've given you one of the forces in the y-direction already, 75N . Since they mentioned positive y-direction that means upwards. Anything down will be taking as negative so you'll have to change the sign later.

To find the other two forces use Pythagoras because you have the x-direction and the resultant so you'll get one force as.
68^2-60^2 = √1024 = -32N
Change it to positive = 32N

And the other as
100^2-96^2 = √784 = -28
Change it to positive = 28N

Hope you got it x)

Sorry but I can't get it

 

[ZainH]

Sorry but I can't get it

Do you know how to use Pythagoras theorem?

 

[GorgeousEyes]

Do you know how to use Pythagoras theorem?

I don't knw how to use here

 

[ZainH]

I don't knw how to use here

Ok , one second I'll show you.

 

[ZainH]