Mathematics: Post your doubts here!

[sara kamal]

Apply Newton's 3rd law.

Weight attached to s1 = 30N so the rope will apply a force of 30N upwards so tension in s1 is 30N
Now for s2 the total weight becomes 50N so similarly the weight will be 50N

thanku so much.

 

[sara kamal]

http://freeexampapers.com/A-Level/Maths/CIE/2010-Jun/9709_s10_qp_32.pdf
please help me in question q8 part 2

 

[nehaoscar]

You mean A and C? It says the whole system is in equilibrium , so for A and C to stay in equilibrium , the tension in the strings they are attached to must be equal to their weights respectively, thus first string has a tension of 5.5 N and the other string has a tension of W N
In other words, just resolve at A and resolve at C

BTW if in any case, the system is in equilibrium, then the tension is always equal to the weight right?

 

[TheJDOG]

http://freeexampapers.com/A-Level/Maths/CIE/2010-Jun/9709_s10_qp_32.pdf
please help me in question q8 part 2

Read carefully
Here you go I justified everything for you on the sides

 

[TheJDOG]

BTW if in any case, the system is in equilibrium, then the tension is always equal to the weight right?

Yes, if and only if no external force is acting and if the string is vertical

 

[hizirofaki]

part 1 AND 2 plz with pictures plz

 

[hizirofaki]

how to find T and H

 

[TheJDOG]

http://maxpapers.com/wp-content/uploads/2012/11/9709_w14_qp_41.pdf
Q2 plz explain

Here you go
Just draw the axis and resolve

 

[Suhaib]

Thankyou very much.

I have another question. If you or anyone else can answer me , that would be great.

So for motion up a slope, for example a lorry, the examiner uses a number of formulas.

in 9707/42/M/J/12 Q6 ii) he uses WD by car’s engine = (Gain in PE + WD against resistance) + KE gain while in a similar question, in 9709/42/O/N/11 Q6, he uses
WD by DF = PE gain + WD against resistance – KE loss.

Can you please explain the difference to me? When to subtract several forces or add them? I'm also confused whether to add WD against resistance or subtract it. :/

Thankyou.

When its going up the hill and losing its speed then in this case we have to subtract the KE in whole formula e.g u=10 at start of hill , v=5 at top of hill.
Case 2 lorry coming down the hill with increasing speed (Should be shown) KE will be positive and its clear that lorry is losing its PE so PE will be subtracted in the eq.

 

[hizirofaki]

Here you go
Just draw the axis and resolve

solve my question plz

 

[Suhaib]

when a certain quantity decreases u need to subtract it like for KE frmula= 1/2mv^2-u^2
(usually in case of upward inclined plane motion)
so if v is less than u it develops a - negative sign for eg if v=5 nd u =7 then 1/2 m (5^2-7^2) = 1/2 m (25-49) = a - value

and for WD against Fr = its only subtracted to find out some other energy change

if Friction or resistance is present:- (inclined plane)
Wd by driving forc = gain in PE + gain or loss in KE + WD by Fr
suppose change in KE is to b found out and ure given WD by Dr, change in Gpe and WD by Fr then
change in KE would be = WD by Dr - (gain in GPE+WD by Fr) ...........here is the case when u subtract wd by fr from a quantity
Hope u get it

I too had this confusion but not anymore thnx alot , last line was most helpful

 

[The Sarcastic Retard]

M1 : practice this paper : http://themathelp.com/pdf/a level m1.pdf

 

[Suhaib]

M1 : practice this paper : http://themathelp.com/pdf/a level m1.pdf

Your Link is not opening take screenshots and paste here

 

[TheJDOG]

http://maxpapers.com/wp-content/uploads/2012/11/9709_w14_qp_43.pdf
q5 why didnt we take psin or pcos why pnly p ???? help ASAP

Here you go, because p is parallel it really depends on how you're drawing your axis.

 

[TheJDOG]

solve my question plz

Which one? 0.o

 

[Suhaib]

Which one? 0.o

Solve these two plz

 

[TheJDOG]

Here you go for Q5 but for second question can I see the full question? The given information

 

[DESTROYER1198]

please help.. june 2014 p41 Q5 i) how do we find the P.E in terms of x

 

[TheJDOG]

please help.. june 2014 p41 Q5 i) how do we find the P.E in terms of x

Look at my post directly above your post , it's in the attachment , you just have to find height in terms of x

 

[DESTROYER1198]

Here you go for Q5 but for second question can I see the full question? The given information

what a coincidence i was stuck in that question too. Thanx alot