Physics: Post your doubts here!

[Unicorn]

hey, i need to kno a thng abt prac.
ie, can we find out the y-intercept of a graph, by the formula? :/
Rep asap!

well that varies from each formula if they tell u to graph T^2 as y axis and lets say 1/d as x-axis

and the formula is T^2=4kl/d +5c

then you would know that T^2 is y value
4kl is gradient
1/d is x axis
5c would be the y-intecept value

when they give u a formula try to work out where y, x, m and c are

 

[code11]

hey, i need to kno a thng abt prac.
ie, can we find out the y-intercept of a graph, by the formula? :/
Rep asap!

yes we can

 

[A.ELWY 7]

how to find a phase difference???:S

it is either by giving the answer as ( pie rad) or the degree..well lets say that one wavelength (lambda) is equal to half pie..where it is equal to 180 degree,(u must memorize this) then u logically must know that to have 1 pie, then the wavelength must be 2 lambda ..and so it is 360 degree etc..to know the phase difference in a staionary wave measure the wavelength between the 2 points you r asked for, and then the rest is easy
note:if i said anything wrong it's most welcome for any correction

 

[hmlahori]

as we kno tht lamp A res=15,
and all the lamps are similr, so the resistnce shud be equal in all of thm.
so when we are closing S2, S3 the resistnce of thes paralle lamps togthr must be 15, and then adding A, it wll b 45.

but here the resistnce is dec.
so we cn cum to a conclusion tht the res. acroos lamp C is less thn 15.

decreasing of resistnce = short circuit of lamp C! :/

i hope i hv solved ur prob:/

does decreasing of a resistance always result in a short circuit and why?

 

[hmlahori]

hmm oky gud luck .my practical tomorow

well gud luck then!

 

[Oliveme]

Please help me with this question In physics paper 23, question 2 part (c). I have no idea about vector triangles. This is the second time I'm posting my question.
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s10_qp_23.pdf

Thank you very much.

 

[hmlahori]

Can someone please explain these paper 2 questions?

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_qp_2.pdf
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_ms_2.pdf
Q2(b) and Q4(b ii) explanations to these questions?

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_qp_2.pdf
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_ms_2.pdf
Q2(c) How do we solve it???

 

[confused123]

Can someone please explain these paper 2 questions?

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_qp_2.pdf
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_ms_2.pdf
Q2(b) and Q4(b ii) explanations to these questions?

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_qp_2.pdf
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_ms_2.pdf
Q2(c) How do we solve it???

q.2 b) if u will suspend a plumbline from different positions then you can know the centre of gravity. i mean you need to draw 4 lines from vertices and then find their intersection point, that will be below pivot. it will eventually come to rest because centre of gravity is in line with pivot. no turning effect produce as we are applying force on the pivot line. this is what i got from the question.

4 b ii) lets find the approximate are:2 [1/2 into .3 into 0.08 ] = 0.024 m

note: i converted the speed from cm/s into m/s and divided the graph into two triangles.

s 06) q.2 c) resolving forces horizontally: we can see that F cos a and T cos B are the only two horizontal forces. now just equate them, they must be equal so that the system remains in equilibrium. Fcos a = T cos b

ii ) resolving vertically: there are two forces acting upwards which are F sin a and T sin b , these two upward forces must equal with the downward weight. hence Fsin a + T sin b = W

iii) sum of moments at A) F doesn't contribute as it is acting at the pivot. o moment by force F.
now we know that AC = 2/3 Ab
the upward force is T sin B and downward is W. the distance of W from A in terms of AB is 2/3 , the distance of T sin B is equal to AB from A point. . now the equation becomes 2/3 AB into W = T sin b into AB , which further becomes 2W= 3T sin b. hope that helps.

can you give your opinion on this question b part?

 

[iKhaled]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s07_qp_31.pdf

need help with the 2nd question. what is the difference between the distance of centre mass and the vertical displacement of the ball? :S:S:S

 

[confused123]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_qp_31.pdf

need help with the 2nd question. what is the difference between the distance of centre mass and the vertical displacement of the ball? :S:S:S

centre of mass means the geometrical centre of the ball where all mass seems to be concentrated. so just pull it down and note the vertical displacement or vertical height in other words at the instant when it is pulled.

 

[confused123]

hey ppl, need help with this!!
Q 3 d i)

someone have a try..

 

[kristf]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w08_qp_31.pdf
question 1g ??​

 

[iKhaled]

need help on how to use a microscrew guage and vernier capillaries plssssss :/

 

[Goku]

Practical in a few hours InshaAllah,releated to heat,please help and give suggestions ?

 

[Arpit17]

Practical in a few hours InshaAllah,releated to heat,please help and give suggestions ?

For experiments involving temperature!

• Readings should be accurate to fractions of a degree.
• Stir any liquid being heated.
• Insulate the apparatus if possible.
• The thermometer should not be touching the sides of the container it is in, and should be in the middle of the liquid you are measuring the temperature of.
• Precaution: read the thermometer at eye level to avoid parallax error.
• The bulb of the thermometer should be completely submerged.
• Comment on the result obtained being the right order of magnitude.

​

 

[Unicorn]

need help on how to use a microscrew guage and vernier capillaries plssssss :/

here

 

[Bama Boy]

Hi lil help here pls. Question is : A beam of red light had twice the intensity of another beam of same color.Calculate the ratio of the amplitudes of the waves. THank you!

 

[Unicorn]

Hi lil help here pls. Question is : A beam of red light had twice the intensity of another beam of same color.Calculate the ratio of the amplitudes of the waves. THank you!

I=A^2

so red light is ---> root(2I)=A

and other light is A'=root(I)

then divide A' by A to get the ratio

which will be root(I)/root(2I)

 

[Bama Boy]

I=A^2

so red light is ---> root(2I)=A

and other light is A'=root(I)

then divide A' by A to get the ratio

which will be root(I)/root(2I)

yep i tried it but i guess it will be A divided by A' so root (2I)/root(I) and then yea i got the correct answer.Thanks for the method mate

 

[anonymous123]

wat is the extension produced? plz help