Physics: Post your doubts here!

[gary221]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_21.pdf
Question four.Part b. (i). Please explain the answers a little bit too.

Principle of superposition = when 2 or more waves meet at a point, the resultant displacement is the sum of the displacements of the individual waves.
White light produced ---> maxima is formed at that point
maxima is only formed when constructive interference takes place.
So, the waves coinciding at that point have the same path difference ---> the waves r in phase.
Hope u gt it!

 

[Buzzkiller]

Principle of superposition = when 2 or more waves meet at a point, the resultant displacement is the sum of the displacements of the individual waves.
White light produced ---> maxima is formed at that point
maxima is only formed when constructive interference takes place.
So, the waves coinciding at that point have the same path difference ---> the waves r in phase.
Hope u gt it!

Got it.But you didn't explain the part that came after this.Red and blue light wala.

 

[A star]

Got it.But you didn't explain the part that came after this.Red and blue light wala.

to obtain maximum path difference the path difference must be lambda
lambda of red and blue light is defferent
so will form at different angles

 

[Buzzkiller]

to obtain maximum path difference the path difference must be lambda
lambda of red and blue light is defferent
so will form at different angles

Why to obtain the max path difference ,the path difference should be lambda?

 

[A star]

because there constructive interference is being done

 

[daredevil]

Can some one please post the physics formula sheet here...
Also is its possible can some one please explain uncertainity and it's usage by formula

uncertainty is basicallly the absolute error/magnitude
for example if L= 14.2 +/-0.01 m
then the uncertainty will be 0.01/14.2

and percentage uncertainty will be to multiply the last value with 100 : -
(.01/14.2)x100

 

[Jiyad Ahsan]

okay help me out on this one.. 9702/21/J/09, Q5 (b)

 

[daredevil]

there are certain approximation values that we need to know...
like the density of air at rtp and stp, the wavelengths and frequencies of each lectromagnetic wave (inclludng of all the colours of the spectrum) and stuff like that....
if u people are aware of it can u pleeaase pot them up here?? thankss

 

[daredevil]

okay help me out on this one.. 9702/21/J/09, Q5 (b)

i'll check out ur question but meanwhile can u tell me that in Q6 bii of the same paper why can't we use the formula v=s/t ??

 

[daredevil]

okay help me out on this one.. 9702/21/J/09, Q5 (b)

ok i didn't get it -__-

 

[daredevil]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w09_qp_22.pdf

okaays
plz explain to me
Q2b(ii) 2.
Q4cii
Q5 a(ii); b; c(ii)

of this paper and explain the answers too plzzz

 

[Ahmedraza73]

Can some one please post the physics formula sheet here...
Also is its possible can some one please explain uncertainity and it's usage by formula

Here is the formula sheet u have asked for:

 

[minie23]

Principle of superposition = when 2 or more waves meet at a point, the resultant displacement is the sum of the displacements of the individual waves.
White light produced ---> maxima is formed at that point
maxima is only formed when constructive interference takes place.
So, the waves coinciding at that point have the same path difference ---> the waves r in phase.
Hope u gt it!

Principle of superposition : It states that whenever waves are travelling and meeting in the same region, their resultant displacement due to the waves at any point is given by the vector sum of their individual displacement at that point

 

[Jiyad Ahsan]

there are certain approximation values that we need to know...
like the density of air at rtp and stp, the wavelengths and frequencies of each lectromagnetic wave (inclludng of all the colours of the spectrum) and stuff like that....
if u people are aware of it can u pleeaase pot them up here?? thankss

righto
mass of a person = around 70kg
height of a person = 1.5m
density of water = 300 cm^3
weight of an apple = 1N
typical current in domestic appliances = 13 A
e.m.f of a car battery = 12 V
density of air at STP = 1.293 kg/m^3

since the wavelength and frequencies are related by V=freq. x wavelength, and since v of all E.M waves is 3.0 x 10^8
just remember one of them.. i'll put them up

 

[gary221]

Principle of superposition : It states that whenever waves are travelling and meeting in the same region, their resultant displacement due to the waves at any point is given by the vector sum of their individual displacement at that point

haan yes.. thts almost the same thing..
the defn i gave is thr in r coursebk..

 

[A star]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w09_qp_22.pdf

okaays
plz explain to me
Q2b(ii) 2.
Q4cii
Q5 a(ii); b; c(ii)

of this paper and explain the answers too plzzz

this paper makes me feel liike a idiot

 

[sma786]

Can some one please post the physics formula sheet here...
Also is its possible can some one please explain uncertainity and it's usage by formula

Its in the syllabus

 

[Jiyad Ahsan]

http://www.google.com.pk/imgres?cli...bnh=178&tbnw=283&start=0&ndsp=21&tx=149&ty=56

^ check this image... i think its detailed enough

 

[daredevil]

this paper makes me feel liike a idiot

haii na!! same here!! :O

 

[minie23]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w09_qp_22.pdf

okaays
plz explain to me
Q2b(ii) 2.
Q4cii
Q5 a(ii); b; c(ii)

of this paper and explain the answers too plzzz

2(b)(ii) seperation of atoms in the cube, V = r^3
r = (1.8x10^-23)^1/3 = 2.6x10^-8 cm

4(c)(ii) 1. Change in Ep = mg(changein h)
= 3.8 x (0.178-0.163) = - 0.057 (-ve since potential energy decreases)

2. Change in elastic P.E = 0.5k( x2^2 - x1^2)
= 0.5x180( 0.036^2 - 0.021^2)
= 0.077 J

(c)(ii) It is the speed of either one of the progressive waves travelling along oppsite directions that have superposed to form the stationary wave after the wave has been reflected at P

Hope this helps !