Physics: Post your doubts here!

[Thought blocker]

can someone give some notes on
CHAPTER 12 : RESISTANCE AND RESISTIVITY.
THANKS IN ADVANCE.

 

[♣♠ Magnanimous ♣♠]

EXPLAIN THE POINTS:
20,19,11,9,7

 

[♣♠ Magnanimous ♣♠]

Thought blocker.explain the above points.

 

[Thought blocker]

Which points ?

 

[♣♠ Magnanimous ♣♠]

the points which i quoted.
the points in your file
20,19,11,9,7

 

[Thought blocker]

the points which i quoted.
the points in your file
20,19,11,9,7

Come in yahoo!

 

[♣♠ Magnanimous ♣♠]

Come in yahoo!

okay.

 

[TheStallion-Reborn]

It would be great if someone could kindly help me with this :/

 

[madoka]

okay.

stupid khud to bohat smart samjtai ho

 

[madoka]

the points which i quoted.
the points in your file
20,19,11,9,7

what u think of your self

 

[mahabaloch]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s03_qp_1.pdf
someone please help me with Q20 and 32

 

[Suchal Riaz]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s03_qp_1.pdf
someone please help me with Q20 and 32

 

[Suchal Riaz]

It would be great if someone could kindly help me with this :/

 

[taffycandy]

hey can u help me with this question
Q) a certain charge Q is dived into two parts q and Q-q,which are then separated by a certain distance.what must q be in terms of Q to maximize the electrostatic repulsion between the two charges?
Q)
two free particles (that is,free to move )with charges +q and +4q are at distance L apart . A third charge is placed so that the entire system is in equilibrium is unstable.

 

[♣♠ Magnanimous ♣♠]

what u think of your self

means.

 

[♣♠ Magnanimous ♣♠]

stupid khud to bohat smart samjtai ho

nahi to.

 

[mehria]

Re: Physics Help here! Stuck somewhere?? Ask here!

can some1 give me vector notes for physics for As level plzzz?????

http://www.s-cool.co.uk/a-level/phy...evise-it/vectors-and-scalars-whats-the-differ
http://www.s-cool.co.uk/a-level/phy...n/revise-it/resolving-vectors-into-components

 

[yousef]

Question 9 (b)

 

[mehria]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s03_qp_1.pdf
someone please help me with Q20 and 32

Q20:- As:- P=ρɡɦ
Where P= pressure
ρ= Density
ɦ= height
So:- ɦ= p/ρɡ
And 10% of p0 is multiplied with the equation

h=

p0 x p/ρɡ = p0/10ρɡ

Q32:- Whenever u are asked to find the Current in a circuit then always use terminal voltage instead of e.m.f of battery..as some of the voltage is used up by the internal resistor
i.e. I= V/R = 7.5/15= 0.5A

 

[sagar65265]

hey can u help me with this question
Q) a certain charge Q is dived into two parts q and Q-q,which are then separated by a certain distance.what must q be in terms of Q to maximize the electrostatic repulsion between the two charges?
Q)
two free particles (that is,free to move )with charges +q and +4q are at distance L apart . A third charge is placed so that the entire system is in equilibrium is unstable.

Q1) Suppose the particles are separated by a particular distance x, and their charges are as you have mentioned, one with a charge "q" and another with charge "Q-q".

Then, the coulomb force acting between them would be equal to:

F(Coulomb) = kq(Q-q)/x^2

Now, we want to know what values of q (in terms of Q) will result in the greatest force on each. Therefore, we want to find the maximum value of F(Coulomb) as q varies.

Therefore, we take the derivative of F(Coulomb) with respect to q and equate that to zero as follows:

d[F(Coulomb)]/dq = kQ/x^2 - 2kq/x^2

Setting this to zero, we get kQ/x^2 = 2kq/x^2
Cancelling out k and x^2, we get:
Q = 2q
q = Q/2

Substituting this value into the equation for F(Coulomb) we get
F(Coulomb) maximum value = kQ^2/(2x^2) Newtons

Q2) I can't really understand this question; is the final situation supposed to be stable or unstable? What is the magnitude of the charge to be placed between the +q and +4q charges?

Good Luck for all your exams!