Physics: Post your doubts here!

[Wolfgangs]

Can someone please give me the answer for this question? The answer is A, right?

 

[shayista547]

Help please! :' I can not understand what happens when cells in a battery are wrongly connected like in the following 2 questions.Thanks in advance guys
Question 1 )
Five cells of emf E are connected in series each having internal resistance r. if due to oversight, one cell is connected wrongly, then the equivalent emf and internal resistance are

[a]3E and 5r 2E and 3r

[c] 4E and 5r [d]5E and 3r

question 2)

 

[shayista547]

Can someone please give me the answer for this question? The answer is A, right?

Yea me too i think the answer is A as constant speed implies that acce=0
therefore 0=driving force i.e F _ opposing force i.e f
therefore f=F.
Can anybody confirm please

 

[Wolfgangs]

At which point does the body comes to momentarily rest?

 

[shayista547]

Sketch graph with labelled axes to show how current through the wire will vary with p.d. across it if temperature increases as current increases.Can anybody help me out please

 

[A*(a*)]

AS physics classified upto 2015 variants included,
https://payhip.com/b/LUjF

 

[Akshajistari]

Hi! Where can I find solved Physics MCQ Papers? (9702)

 

[nehaoscar]

Hi! Where can I find solved Physics MCQ Papers? (9702)

http://physics-ref.blogspot.in/2014/05/physics-9702-notes-worked-solutions-for.html
Check on here

 

[Akshajistari]

Thank you so much nehaoscar !

 

[Instigator]

i got my midterms from Tuesday someone HELP !

Questions >>> 16 , 17
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s11_qp_12.pdf

questions >>> 5 , 9 , 12 , 21
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w14_qp_12.pdf

Physicist nehaoscar shayista547

 

[nehaoscar]

Questions >>> 16 , 17
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s11_qp_12.pdf

16.
Take moments about X
Suppose the distance between X and Y is a
Then : aFsin(30) = 10(0.5a)
Fsin(30) = 5
F = 10N

 

[nehaoscar]

i got my midterms from Tuesday someone HELP !

Questions >>> 16 , 17
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_12.pdf

nehaoscar shayista547

17.
Find angle PXY using sine rule
(sin(90)/50) = (sin(x)/40)
this gives x as 53.1 degrees
now use 2Fcos(x) since tension from both ropes adds up to the resultant
2(4cos(53.1)) = 4.8N

 

[nehaoscar]

questions >>> 5 , 9 , 12 , 21
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w14_qp_12.pdf

5.
On earth
2s = at^2
4 = at^2
a = 4/(t^2)

On moon
2s = (a/6)T^2
4 = (4/6t^2)T^2
T^2 = 6t^2
T = sqaureroot(6) x t^2

 

[nehaoscar]

questions >>> 5 , 9 , 12 , 21
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w14_qp_12.pdf

9.
initial momentum = 3mv - 2mv
=mv
final momentum (conservation of momentum)
mv = 4mw where w is the final vellocity
w = v/4

 

[Instigator]

9.
initial momentum = 3mv - 2mv
=mv
final momentum (conservation of momentum)
mv = 4mw where w is the final vellocity
w = v/4

nehaoscar i wud be incredibly great full if u cud solve question 12 and 21 frm p12 oct 2014 aswell , thank u !!!

 

[Tozu Fofo]

Can someone please explain to me what do they mean by "use graphical methods to represent distance, displacement, speed, velocity and acceleration" (From Kinematics unit in the syllabus)?

 

[Instigator]

Can someone please explain to me what do they mean by "use graphical methods to represent distance, displacement, speed, velocity and acceleration" (From Kinematics unit in the syllabus)?

i think what they mean is that u sketch a graph of distance,speed , acceleration etc.

 

[Instigator]

can some also explain >>> Q- 9 ,8 http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_12.pdf

 

[nehaoscar]

nehaoscar i wud be incredibly great full if u cud solve question 12 and 21 frm p12 oct 2014 aswell , thank u !!!

12.
Take moments about the bottom left corner
clockwise = aniti-clockwise moments
Fh + Wa = 2Wa

21.
Strain energy is the area under the graph
Break the graph into sections and calculate the area
Remember to multiply the length by 10^-2 since it's in cm

 

[nehaoscar]

can some also explain >>> Q- 9 ,8 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_12.pdf

9.
height h will decrease since it's dropped from top to bottom
So the option is between A and B
The velocity is the gradient
Velocity is not constant since there is acceleration so the gradient is not constant
so it's A