Physics: Post your doubts here!

[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

 

[Mohammed salik]

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

You'r Welcome!

 

[Taimoor Tee]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_43.pdf
Q.5 aii

 

[Ddberry]

can someone please explain the bird question and the turbine question. (question 2 and question 3) please reply ASAP
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_32.pdf

 

[MiniSacBall]

can someone please explain the bird question and the turbine question. (question 2 and question 3) please reply ASAP
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_32.pdf

If i am not wrong you have posted in the wrong section/thread. This is for AS And A Level.

 

[hope4thebest]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w11_qp_41.pdf
Question 4 part a. Help needed

 

[sma786]

Ok so A simple question..
Why would Power be zero when resistance would be O or also infinity?
Why would power be zero in both the cases? :/