Hyperblade01 Question Thread

[hyperblade01]

To be honest it was only the last part that screwed me over..



THANK YOU VERY MUCH -

But can I be like 99% safe to assume this kinda of question would not be on the exams? If they could be, would it just be a calculator question...?

[TrueTears]

I've asked my teacher, says it would be most unlikely to be on exam but who knows.

[TrueTears]

Actually the theory of linear substitution is definitely in the course which is how to integrate that integral.

[hyperblade01]

Actually the theory of linear substitution is definitely in the course which is how to integrate that integral.

I do know about linear substitution, just haven't been exposed to a question like this before



Don't know if you got what I was trying to say - it's possible that the above would be a possible question, but I'm asking whether the original question would be. I mean, 3 pages of working IS a bit crazy...

I'll be asking MY teacher tomorrow so yea


(Forgot to give the +1 )

[TrueTears]

heh yeah I asked my teacher about if we'd get something like that. He just went  :buck2: and said maybe yes maybe no =S

[hyperblade01]

Is someone able to show the working for converting        to        ?

Thanks in advance

[kamil9876]

[hyperblade01]

I've gotten the answer and I've used two extra variables, u and Z, with some substitution involved

At one point I reached:




Is there a way to anti diff that log without first diff-ing then muddling around to find it equals ? Or do you just have to just memorise it...

[TrueTears]

Integration by parts, read on it in wiki.

[hyperblade01]

Two chemicals, A and B, are put together in a solution where they react to form a compound, X. The rate of increase of the mass, x kg, of X is proportional to the product of the masses of the unreacted A and B present at time t minutes. It takes 1 kg of A and 3kg of B to form 4kg of X. Initially 2kg of A and 3kg of B are put together in solution. One kg of X forms in one minute.


a) Set up the appropriate differential equation expressing as a function of x.

The rest, i can probably do without much trouble...

[hyperblade01]

b)

Do I resolve the pulling force into i and j components? If so, i've done that but dunno which forces I need to equal with Pcos35


Sorry if I'm using incorrect terminology

[kamil9876]

tension in the second string(one connecting the two blocks) and friction is acting opposite to Pcos35. However it's not exactly equal to it since netforce is non-zero.

[hyperblade01]

Correct working?

R = ma + uN
50 = 15*2 + u*15g
50 = 30 + 15gu
20 = 15gu
u = 20/15g
u = 4/3g as required

(I combined the masses to give 15kg and then combined N to give 15*g)



Btw whats the latex code for 'mew'?

[Damo17]

(Image removed from quote.)

Correct working?

R = ma + uN
50 = 15*2 + u*15g
50 = 30 + 15gu
20 = 15gu
u = 20/15g
u = 4/3g as required

(I combined the masses to give 15kg and then combined N to give 15*g)



Btw whats the latex code for 'mew'?

Yes, that is correct working.

Code: [Select]

[tex]\mu[/tex]

[hyperblade01]

Thanks, another question:

a) was worth 3 marks, where do they get distributed?

1 for answer
1 for correct initial equation
1 for working

??

The suggested answers went kinda overboard imo but my answer seems a bit short for 3 marks...