Physics: Post your doubts here!

[abcde]

^Well-explained.

How do you solve Q12, Q13 and Q14 of the November 2009 variation 11 paper?

Q12.
Consider all forces acting on the nail. Since the same picture is used and it is balanced in both cases, the vertical sum of the tensions would equal the upward vertical force. Thus, R1 = R2.
Extend R1 and R2 downwards using a dotted line. Suppose the angle made by T1 with the dotted line is x and that by T2 is y.
Now, 2 T1 cos x = R1 and 2 T2 cos y = R2
=> 2 T1 cos x = 2 T2 cos y
Since x > y, cos x < cos y. For the equation to hold true, T1 must be greater than T2. So B is correct.

 

[BeeBee]

please can someone derive an expression for the pressure exerted by root mean speed of a gas in a container?

 

[ffaadyy]

please can someone derive an expression for the pressure exerted by root mean speed of a gas in a container?

P = (1/3) x [(Nm)/V] x <c^2.

N = number of molecules
m= mass of 1 molecule
V = volume of the gas
<c^2> = mean squared speed

or

P = (1/3) x (ρ) x <c^2>

ρ = density

 

[XPFMember]

As-salam-o-alaikum!

Update: Link to topical papers added to the first post....

Here are the compiled A level topical Physics questions in PDF form...

Paper 1 : http://www.mediafire.com/?tocg6ha6ihkwd

Paper 2 & Paper 4 : http://www.mediafire.com/?g65j51stacmy33c

(Source : http://www.alevelforum.com/viewtopic.php?f=15&t=14)

 

[rz123]

^Thank you very much for these additions but do u have the answers and marking schemes to the worksheets on the webs u mentioned.

 

[XPFMember]

^Thank you very much for these additions but do u have the answers and marking schemes to the worksheets on the webs u mentioned.

Firstly, assalamoalaikum wr wb!

So as far as I remember, these include the years and question papers....they're exact pages from the pastpapers...isnt it? I didnt check P1 but I remember checking p2 / p4 ....
Just check that again...
SO you could get the answers by checking out the corresponding markschemes.

 

[rz123]

hmm Walekum Salaam warhamutalahe barkata hu, Ya Ahlan Wahsalan.

i was talking bout P1 , no answers and its not possible to check each and every mcq by going thru different years marking schemes..i lost the cd which i got with David Sang physics book which had worksheets plus answers so if u have that then kindly upload the answers of those worksheets. tnx n Allah hafiz

 

[XPFMember]

hmm Walekum Salaam warhamutalahe barkata hu, Ya Habiibi Ahlan Wahsalan Maulana Greetings! jk

i was talking bout P1 , no answers and its not possible to check each and every mcq by going thru different years marking schemes..i lost the cd which i got with David Sang physics book which had worksheets plus answers so if u have that then kindly upload the answers of those worksheets. tnx n Allah hafiz

I'm sorry, I don't have that..

 

[rz123]

its ok . N.p

 

[omg]

any good site or notes for phy applications??

 

[Arshiful]

Please anyone help me with this question with explanation!

 

[Arshiful]

 

[Arshiful]

someone pls answer my question!! r e bhai koi to mujhe iss sawal ka jawab dijiye !

 

[unique840]

emf = change in magnetic flux linkage per unit time
= NBA/t
N, A and t are constant
B is changing.
emf is directly proportional to -B (lenz's law)
B= F/IL
B is inversely proportional to I
means emf is negative gradient of I
the graph is divided in 4 parts
in the first part, I is zero, so there is no emf induced.
in second part, gradient is from max to zero, so emf will be max to zero in the negative direction.
in third part gradient is zero so emf is zero
in the last part, gradient is zero to maximum so emf will be from zero to maximum in the negative direction
part 1 and 3 = horizontal line on x-axis
part 2 and 4 = max to zero and zero to max respectively in negative directions

 

[unique840]

 

[Arshiful]

View attachment 3741

thnx !!! thnx a lot!

 

[unique840]

thnx !!! thnx a lot!

ur welcum

 

[hassam]

any good site or notes for phy applications??

check out my physics chem bio application thread.....there i have posted many links for youtube lecture vids specific to application topics

 

[hassam]

View attachment 3741

brother : firstly u cant use F=BIL here cos its a solenoid kind of arrangement!
bt however....the result from solenoid formulae will be the same....i.e E ends up being proportional to -dI/dt since(B=knI)(wid k being a constant and n number of turns)
the main problem is the graph u drew......
do correct me if u think i m doing a mistake

 

[omg]

lin

check out my physics chem bio application thread.....there i have posted many links for youtube lecture vids specific to application topics

link for that thread ? :/