Physics: Post your doubts here!

[ZaqZainab]

20) Answer is 0.11
21) Answer is correct Ty
37) Answer is proton
39) Answer is B
40) Answer is A
Btw ty

20) answer is 0.11 cause of the curve it is not a straight line? when you find the area under the curve you used the equation of area of a triangle cause there no other way they have not even given us boxes so after finding the area of a triangle thats not it cause it not a proper triangle you missed a little bit so it makes it 0.11 and not 0.10 it would be 0.10 if it was a proper triangle but it is'nt got it?
37) the guy has explained it quite well
39)(I am sorry about this one i messed up the paper i had many tabs open) sorry this one is B why you ask the closer you get to the nucleus the greater the charge field
so the closer the alpha particle to the nucleus the more the repulsion
40) sorry my method is correct but if you do it you get A *face palms*
if you derive the units for A B C D you get
A: N kg–1 * kg m–3*m*m^3 = (kg⋅m⋅s−2)kg–1* kg m–3*m*m^3= you get kg⋅m2⋅s−2 <----- which is joules If you do the others you won't
i did not do any of the calculations by i did give you the way if you followed it you would have got A sorry about saying B I had opened the wrong MS No wonder so many wrong my deep apologize I hope you get it now sorry again

 

[meerul264]

Need some help with these questions..

(9702/02/m/J/05)
Q 5(b)(iii) and 5(c)
http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s05_qp_2.pdf

(9702/2/M/J/03)
Q 4(b)(ii)
Why when the distance D is increased to 2D, the maximum brightness of the fringes becomes less bright?
And why when the wavelength l is increased to 1.5l, the maximum brightness of the fringes becomes less bright?
http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s03_qp_2.pdf

 

[ZaqZainab]

(9702/2/M/J/03)
Q 4(b)(ii)
Why when the distance D is increased to 2D, the maximum brightness of the fringes becomes less bright?
And why when the wavelength l is increased to 1.5l, the maximum brightness of the fringes becomes less bright?
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s03_qp_2.pdf

Q4bii as D changes to 2D the fringe separation increases you agree to that right?
Intensity=power/area in this case power stays same so more the area the light is falling on increases so less the intensity so less bright
wavelength =(ax)/D
a and D are constant so more the wave length more the separation (x)
and yeah more the x more the area decreasing the intensity

 

[meerul264]

Q4bii as D changes to 2D the fringe separation increases you agree to that right?
Intensity=power/area in this case power stays same so more the area the light is falling on increases so less the intensity so less bright
wavelength =(ax)/D
a and D are constant so more the wave length more the separation (x)
and yeah more the x more the area decreasing the intensity

I see... thanks! So if the fringe seperation (x) is increased -> the diameter of light falling increases -> area of light falling increases -> intensity decreases

 

[The Godfather]

Sorry if my explanation was not clear, but yes the answer is proton.

But the question was that whether the particle that have the same value in the nucleus of isotope is either electron or proton.
So that correct answer would be proton because proton is located within the nucleus,
but electron is orbiting outside the nucleus.

Ty man!

20) answer is 0.11 cause of the curve it is not a straight line? when you find the area under the curve you used the equation of area of a triangle cause there no other way they have not even given us boxes so after finding the area of a triangle thats not it cause it not a proper triangle you missed a little bit so it makes it 0.11 and not 0.10 it would be 0.10 if it was a proper triangle but it is'nt got it?
37) the guy has explained it quite well
39)(I am sorry about this one i messed up the paper i had many tabs open) sorry this one is B why you ask the closer you get to the nucleus the greater the charge field
so the closer the alpha particle to the nucleus the more the repulsion
40) sorry my method is correct but if you do it you get A *face palms*
if you derive the units for A B C D you get
A: N kg–1 * kg m–3*m*m^3 = (kg⋅m⋅s−2)kg–1* kg m–3*m*m^3= you get kg⋅m2⋅s−2 <----- which is joules If you do the others you won't
i did not do any of the calculations by i did give you the way if you followed it you would have got A sorry about saying B I had opened the wrong MS No wonder so many wrong my deep apologize I hope you get it now sorry again

Come on! No need of sorry! TY

 

[Mustafa Malik]

Hello I am confused wd am physics practical. I scored really bad 27 n I don't understand decimal places and sig fig for various instruments.

 

[ijlalm]

Q: A child (mass m) sits on a car seat which is accelerating horizontally at 0.50g (where g is the acceleration of free fall).
What is the magnitude of the total force exerted by the car seat on the child?

A. 0.50mg B. 1.0mg C.1.1mg D1.5mg

 

[ZaqZainab]

Q: A child (mass m) sits on a car seat which is accelerating horizontally at 0.50g (where g is the acceleration of free fall).
What is the magnitude of the total force exerted by the car seat on the child?

A. 0.50mg B. 1.0mg C.1.1mg D1.5mg

is the answer C?
if so i will explain how i got it

 

[ijlalm]

yes its C surely
i also figured out the solution
thnx anyway..

 

[The Godfather]

is the answer C?
if so i will explain how i got it

Tell me how ?

 

[ijlalm]

If the seat is accelerating horizontally then there is a force of o.5 mg acting in the horizontal direction on the child.

There is also a force of 1 mg acting upwards on the child to prevent them falling under gravity

Use pythagoras to calculate the hypotenuse and hence the magnitude of the resultant force.

Even without doing the calculations you must realize that it has to be greater than 1mg but can't be equal to the sum of the two (1.5mg) unless the forces were acting in the same direction.

So there is only one answer in this range.

 

[The Godfather]

If the seat is accelerating horizontally then there is a force of o.5 mg acting in the horizontal direction on the child.

There is also a force of 1 mg acting upwards on the child to prevent them falling under gravity

Use pythagoras to calculate the hypotenuse and hence the magnitude of the resultant force.

Even without doing the calculations you must realize that it has to be greater than 1mg but can't be equal to the sum of the two (1.5mg) unless the forces were acting in the same direction.

So there is only one answer in this range.

ty

 

[leadingguy]

Can Anyone tell me the physics(9702) syllabus topics of electricity portion of As-level??
I have seen the 2014 syllabus. on cie.org still....
If anyone can specify the main topics of the syllabus electricity portion for As level????
like Milikan's oil drop experiment, kirchhof's rules. ect

 

[ZaqZainab]

Can Anyone tell me the physics(9702) syllabus topics of electricity portion of As-level??
I have seen the 2014 syllabus. on cie.org still....
If anyone can specify the main topics of the syllabus electricity portion for As level????
like Milikan's oil drop experiment, kirchhof's rules. ect

Electric Filed
Attraction and repulsion
investigating electric fields
Electric Field strength
Force on a charge"

Electric current,potential difference and resistance
Circuit symbols and diagrams
Electric current
The meaning of voltage
electrical resistance
Electrical power

Kirchhoff's law first law
second law
applying
resistor combination
Ammeters and voltmeters

Resistance and Resistivity The I-V characteristics for a metallic conductor
Ohm's law
Resistance and temperature
Resistivity

Practical circuits
Internal resistance
Potential divider
Potentiometer circuits

Source: Book recommended by CIE(Physics coursebook)

 

[leadingguy]

Electric Filed
Attraction and repulsion
investigating electric fields
Electric Field strength
Force on a charge"

Electric current,potential difference and resistance
Circuit symbols and diagrams
Electric current
The meaning of voltage
electrical resistance
Electrical power

Kirchhoff's law first law
second law
applying
resistor combination
Ammeters and voltmeters

Resistance and Resistivity The I-V characteristics for a metallic conductor
Ohm's law
Resistance and temperature
Resistivity

Practical circuits
Internal resistance
Potential divider
Potentiometer circuits

Source: Book recommended by CIE(Physics coursebook)

Thanks loads + the E = -V relation is present in As ?? or part of A2??
And thank you very much.

 

[ZaqZainab]

Thanks loads + the E = -V relation is present in As ?? or part of A2??
And thank you very much.

Nope it actually I-V graph
its even mentioned in the syllabus
sketch and explain the I-V characteristics of a metallic conductor at
constant temperature, a semiconductor diode and a filament lamp

 

[Thought blocker]

Can Anyone tell me the physics(9702) syllabus topics of electricity portion of As-level??
I have seen the 2014 syllabus. on cie.org still....
If anyone can specify the main topics of the syllabus electricity portion for As level????
like Milikan's oil drop experiment, kirchhof's rules. ect

Let me give you notes to prepare from.. If you need more, tell me..
I have attached questions too..
I got this awesome notes from this site It helped me alot, hope it help you too Tc...

 

[Thought blocker]

Nope it actually I-V graph
its even mentioned in the syllabus
sketch and explain the I-V characteristics of a metallic conductor at
constant temperature, a semiconductor diode and a filament lamp

As level gurl ?

 

[ZaqZainab]

As level gurl ?

Yup its on page 26 (i) and its not bold so yeah AS level and its in part of the coursebook where there is AS

 

[Thought blocker]

Yup its on page 26 (i) and its not bold so yeah AS level and its in part of the coursebook where there is AS

hahaha I mean Are u AS level girl ?