Physics: Post your doubts here!

[sweetjinnah]

Hello,
I didn't understand how you solved this part of the question. How did you get N/No = 1/10?
I'll be really grateful if you could explain the whole solution in detail.
Jazakallah

see my wall discussion with Hadi Murtaza.. Hadi Murtaza plz help this person

 

[Anikaa]

7 c (ii) n 9 b (ii) please!
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s11_qp_41.pdf

 

[Anikaa]

hi can someone explain to me how to do question 1 b (ii)
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_4.pdf

T=m(w^2)r +mg
kx =m(w^2)r +mg

 

[sma786]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s07_qp_2.pdf

Question 6, (a ii).. Why is the EMF (14-E) ?

 

[misaki ayuzawa]

Ok...i hav recently strted phy p4...
nd i hate phy...i usually get lame lame doubts from phy...so i hope u dnt get annoyed when u see my doubts
ques: May-June 2009 phy p4
Que 1.part b
for da diameter we shud divide it by 2...nd find da mass
but i dnt get my ans...
plzzz any1 solve it...
P.S. I nid it ASAP

 

[salvatore]

see my wall discussion with Hadi Murtaza.. Hadi Murtaza plz help this person

I can't find the wall post. Waiting for help from Hadi Murtaza

 

[sma786]

I can't find the wall post. Waiting for help from Hadi Murtaza

Love your username

 

[hope4thebest]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_43.pdf
People please can anyone explain 5(c) (ii) ? May Allah bless you all!

 

[sma786]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_2.pdf

Question 1 (b).. Found the percentage uncertainity of R as 1.9%.. percentage removed would give 0.019cm ... Then why is the answer 0.009cm?

 

[Mohammed salik]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_2.pdf

Question 1 (b).. Found the percentage uncertainity of R as 1.9%.. percentage removed would give 0.019cm ... Then why is the answer 0.009cm?

That Percentage is The uncertainity in R.. So its 1.9% of R value.
Which is 0.0489.
Now You will have to :

1.9/100 * 0.048 = 9*10^-3 = 0.009 cm :3

 

[Hadi Murtaza]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_2.pdf

Question 1 (b).. Found the percentage uncertainity of R as 1.9%.. percentage removed would give 0.019cm ... Then why is the answer 0.009cm?

% uncertainty = (uncertainty/reading) * 100
1.9% = (uncertainty/0.4886) * 100
0.019 = uncertainty/0.4886
uncertainty = 0.019 * 0.4886
[ uncertainty ≈ ± 0.009 cm ]

 

[Thought blocker]

% uncertainty = (uncertainty/reading) * 100
1.9% = (uncertainty/0.4886) * 100
0.019 = uncertainty/0.4886
uncertainty = 0.019 * 0.4886
[ uncertainty ≈ ± 0.009 cm ]

wowowowow! Do we follow same for all uncertainty questions ?

 

[Hadi Murtaza]

wowowowow! Do we follow same for all uncertainty questions ?

Yup, im doing edexcel A level n i do it like dat ova der too

 

[sumeru]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s13_qp_22.pdf.....
Q.no.5 b(iii)...A little bit of a help in graph part...anyone?....

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s13_qp_22.pdf.....
Q.no.5 b(iii)...A little bit of a help in graph part...anyone?....

The time period of the stationary wave is 20ms. After 5 ms, it would be a straight horizontal line, drawn on the dotted line. Take a look at this animation and you will understand the logic

 

[sumeru]

The time period of the stationary wave is 20ms. After 5 ms, it would be a straight horizontal line, drawn on the dotted line. Take a look at this animation and you will understand the logic

Can you elaborate a bit more.....I mean, won't the wave travel a further more after 5 sec...and for the wave given isn't the time period 30m/s....a bit confused here....

 

[usama321]

frequence = 50 hz Thus 1/50 = 20ms = time period.
After 5ms, the wave would have travelled through 1/4th of its total distance. Thus after travelling 1/4th of its distance from its highest displacement, the antinodes too will have zero displacement at this time. You can also imagine the wave's path in your head or on the animation. From the top to the bottom, the wave has travelled half of its path. Half of half = 1/4 which would be when the displacement of all the points on it is zero

 

[Harsh Poddar]

I've made this site that can help you to quickly access past papers for a few common subjects. Try it out and please leave a feedback here

http://server-poddarh.rhcloud.com/paper.html

 

[Thought blocker]

Physics, 15 may

 

[sma786]

That Percentage is The uncertainity in R.. So its 1.9% of R value.
Which is 0.0489.
Now You will have to :

1.9/100 * 0.048 = 9*10^-3 = 0.009 cm :3

% uncertainty = (uncertainty/reading) * 100
1.9% = (uncertainty/0.4886) * 100
0.019 = uncertainty/0.4886
uncertainty = 0.019 * 0.4886
[ uncertainty ≈ ± 0.009 cm ]

Thankyou guys :') I figured it out too
But thanks alot