Physics: Post your doubts here!

[kitkat <3 :P]

Can some one please help O/N 2010 variant 22
Q6 (b) please? What is the formula and explanation?

please post the link

 

[DeViL gURl B)]

which part?

(B)

 

[Zepudee]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_2.pdf
PLEASE GUYS HELP ME WITH THIS. Q5(a)!!! Please show some workings!! THANKS A LOT!!!!

 

[sma786]

physics application part communication... The formula
number of decibels = lg(Power out/Power in)

Whats lg here? Is it a constant? What is it's value?

 

[Asad Moosvi]

I can explain you the last part i.e (ii) cuz other parts seem easy.
Wave traveling from S to X moves a distance of 5m.(simple pythagoras theorem i.e (4^2+3^2)^0.5
Wave traveling through SPX moves a distance of 7m.
So whats the path difference? 7-5 = 2m
Since for constructive interference path difference is n lamba, there will be maxima formed at X.

Can you also explain b (i) please?

 

[Zepudee]

(B)

if the voltmeter reading is 4V, then use the formula Vout=V(Total) x RAB/RT
4 is Vout. V total is 9.0 and put your RAB as unknown, RT which consists of RAB and 1.2kohm
Then the total resistance, will be 960 ohm
hehehe understand?

 

[Asad Moosvi]

Asad bhai no need to be confused.Theres a simple concept.In a radioactive decay,both nucleon and proton number are conserved.But the total mass of the particles after decay is less than that before the decay which is because of some loss of energy in the form of electromagnetic radiation.

Thanks yar!

 

[student1415]

look the distance covered in n revolutions =2(pi)nr
workdone = F*s
=F*2(pi)nr

so for torque r is the perpendicular distance
and is the force
T=Fr

pue the formula in Workdone equation
W=2(pi)nT
hope it helped

thank you

 

[DeViL gURl B)]

if the voltmeter reading is 4V, then use the formula Vout=V(Total) x RAB/RT
4 is Vout. V total is 9.0 and put your RAB as unknown, RT which consists of RAB and 1.2kohm
Then the total resistance, will be 960 ohm
hehehe understand?

Okhay okhay ... Thank you sooo much!
That was pretty easy .. Btw!
That formula didn't pop up! -_-
Thank you!!!!

 

[DeViL gURl B)]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_22.pdf

Guys PLEASE someone explain... Question 5 paper 21 !!
B part !
HURRYYY!! Please!!!
Thank u

 

[kitkat <3 :P]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_22.pdf

Guys PLEASE someone explain... Question 5 paper 21 !!
B part !
HURRYYY!! Please!!!
Thank u

umm u have given link of 22 bt you're saying 21 can u confirm which one please ?

 

[kitkat <3 :P]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_22.pdf

Guys PLEASE someone explain... Question 5 paper 21 !!
B part !
HURRYYY!! Please!!!
Thank u

if you're asking for the link you provided then
fot T use the first graph so T=0.6
for wavelength 2nd graph do lamda = 4
v = f*(lamda)
=1/T *(lamda)
1/0.6 * 4
=6.67

 

[DeViL gURl B)]

umm u have given link of 22 bt you're saying 21 can u confirm which one please ?

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s09_qp_2.pdf

I'm sorry! Here u go! Paper 21 btw
And thank u

 

[DeViL gURl B)]

I'm sorr

if you're asking for the link you provided then
fot T use the first graph so T=0.6
for wavelength 2nd graph do lamda = 4
v = f*(lamda)
=1/T *(lamda)
1/0.6 * 4
=6.67

Sorry gave the link

 

[Princess Raven]

Which paper issit?

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w05_qp_2.pdf
Question 5 part c ii

 

[Princess Raven]

Guys how do we know to how many significant figures should we write the percentage error too??

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w05_qp_2.pdf
Question 5 part c ii

The resultant displacement of the two waves at point P would be -1. I = -^2 = 1
Now in terms of I
We know that I is 9 Thus
I/I(part ii) = 9/1
I(part ii) = 1/9 I

 

[usama321]

Guys how do we know to how many significant figures should we write the percentage error too??

The question is about absolute uncertainty. Absolute uncertainty is always given to one significant figure.

 

[Princess Raven]

How

The resultant displacement of the two waves at point P would be -1. I = -^2 = 1
Now in terms of I
We know that I is 9 Thus
I/I(part ii) = 9/1
I(part ii) = 1/9 I

do you know I is 9?? I don't get what u just said

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s04_qp_2.pdf
For Q3. b i, is it okay if I do the work and get -2N and then put the magnitude as 2N? Since I did this question using their vector nature