Physics: Post your doubts here!

[Charlotte20102013]

Suppose that a tank contains 680 m3 of neon at an absolute pressure of 1.01x105 Pa. The temperature is changed from 293.2 to 294.3 K. What is the increase in the internal energy of the neon? [3.9x105 J]

Need help . Thanks in advance!

(This is not a past year question)

 

[Charlotte20102013]

do you have the reference??

2, member: 114812"]do you have the reference??[/

Reference? As in?

 

[Charlotte20102013]

check qu 303 at
http://physics-ref.blogspot.com/2015/01/physics-9702-doubts-help-page-51.html

Thank you!
And the question was provided by my lecturer and no I do not have any idea where he got it from.

 

[Charlotte20102013]

Another question:

An object of mass 0.20 kg tied to a string is made to move in a vertical circle. When the object is at the highest point, the tension in the string is zero. Determine the tension in the string when the object is at the lowest point. [11.8 N]

Thanks!

 

[princess Anu]

why isnt it b? isnt rubber a polymer? and it doesnt follow the hooke's law right? so why a straight line for rubber

 

[Math Buddy]

How to Calculate uncertainties in lg(T/s).

 

[princess Anu]

shouldn't it be A? if we take this as a straight line answer comes 0.1 but since strain energy would will less than this ans should be A ?

 

[Dream.Eater]

Can anyone please explain how to draw two waves with a phase difference?
for example, "draw two waves of identical frequency,wavelength and amplitude and with a phase difference of 5π/8"

any supporting materials or links would also be greatly appreciated
Thanks in Advance!

 

[a_wiserME!!]

does anyone have revision notes for as level physics??
TIA

 

[princess Anu]

why are we using the volune calculated in ii1 for finding separation of atoms and not the volume found in i?

 

[princess Anu]

this is the question i was talking about

 

[Dream.Eater]

it's explained at
http://physics-ref.blogspot.com/2015/01/physics-9702-doubts-help-page-55.html

Thanks a lot!

 

[princess Anu]

why can't it be b?

 

[Math Buddy]

why can't it be b?

i hope you get it

 

[princess Anu]

i hope you get it

but then shouldn't it be 2/1 instead of 1/2?
since Density is inversely proportional to volune right? so ratio of densityp: densityQ should be volumeQ: volume P ,, No?

 

[Paris Palmer]

check qu 315 at
http://physics-ref.blogspot.com/2015/01/physics-9702-doubts-help-page-54.html

When we calculate Escape Speed, we use the formula square root[2GM/R]. Here why do we assume the radius,r, as the radius of Earth,R? Escape speed is the speed with which a body moves from gravitational field to infinity. What if its initial position in the gravitational field from where it escaped to infinity was not on the surface of Earth? Why do we use R? Shouldnt we use r as the distance of its initial position from centre of the Earth?

 

[Xerav43]

Can someone help me with paper 02 may june 2008 question 6)b) ? It's not making any sense no matter what I try to do. Thanks

 

[qdkhan]

salam! Can sum1 please explain the following?
q23 in May june 2012 p23. i understand as to why is it C, but not why the other choices are incorrect.
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_11.pdf
q20 in May june 2011 paper 11
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_11.pdf
q22 and q23 in May june 2013 paper 11
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s13_qp_11.pdf

 

[Paris Palmer]

are you referring to a specific question. if yes, tell me which question it is

If a body is present in the Earth's gravitational field, but not on the surface of Earth, then it escapes to infinity. The formula of its escape speed is square root(2GM/r). Here, why r is taken as the radius of Earth?

 

[Paris Palmer]

No its not a specific question. I am just confused why we always take r as the radius of Earth in the formula of Escape speed?