Physics: Post your doubts here!

[omg]

View attachment 53543
help please thanks

find percentage uncertainity of all the values by the formula absolute/true value * 100. add them. multiply the uncertainity of r by 4. and you should get the answer. and the absolute value is the one in points like 0.001 and the true value is 1.20 waleys.

 

[omg]

what? which one is absolute value and which one is true value? should i take perc. uncertainty as 6.7?

true value is the value of density which is 2.685 and absolute is 6.7%.
(6.7/100 * 2.685) willl give you the answer

 

[Sahil Gupta]

true value is the value of density which is 2.685 and absolute is 6.7%.
(6.7/100 * 2.685) willl give you the answer

Thanks a ton

 

[Abdul Hanan]

find percentage uncertainity of all the values by the formula absolute/true value * 100. add them. multiply the uncertainity of r by 4. and you should get the answer. and the absolute value is the one in points like 0.001 and the true value is 1.20 waleys.

i tried. i still can't lead to the final answer... can you give a brief working please? thanks.

 

[omg]

i tried. i still can't lead to the final answer... can you give a brief working please? thanks.

sure but how do we attach the files here? .-.

 

[Abdul Hanan]

sure but how do we attach the files here? .-.

Drag it from your PC folder to the writing box here. or from phone just click "upload a file" button beside the "post reply button and find the file...

 

[omg]

.

 

[omg]

Drag it from your PC folder to the writing box here. or from phone just click "upload a file" button beside the "post reply button and find the file...

let me know if you dont understand anything

.

 

[Abdul Hanan]

.

let me know if you dont understand anything

Thanks. That helped a lot.

 

[Studydayandnight]

Guys please help me out in the last part of this question!!

It's drawing the graph.

The answers to the previous parts are:

2 b ii) 12.4 seconds and velocity is 1.61 ms^-1

Please helpppp, I drew something but I am not sure if it's correct.

Also, any tips when it comes to drawing graphs like these in physics??

 

[amal sharkawi]

can anyone explain this plz???

 

[amal sharkawi]

View attachment 53502

THANX

 

[Studydayandnight]

How do we do this? :'(

 

[omg]

How do we do this? :'(

what is the answer?

 

[omg]

How do we do this? :'(

Is it 4 or 3.5?

 

[Studydayandnight]

Is it 4 or 3.5?

It's 3.5 so they've rounded it off to 3. :/

 

[Studydayandnight]

How do we do these graph questions?

Fb is 188 N.

I've also attached the question paper!

http://onlineexamhelp.com/wp-content/uploads/2014/08/9702_s14_qp_21.pdf

 

[omg]

It's 3.5 so they've rounded it off to 3. :/

oh okay.
so the formula for diffraction grating is dsintheta= n lambda
we will find d by 1/lines per millimeter
then put it in the formula take theta as 90. and you will get 3.5. round it off to 3.

 

[omg]

How do we do these graph questions?

Fb is 188 N.

I've also attached the question paper!

http://onlineexamhelp.com/wp-content/uploads/2014/08/9702_s14_qp_21.pdf

880 + 200 gives us 1080
upward should be equal to downward forces for the plank to be in equlibrium
so we want 1080 upward force. now look athe graph , when the value of FA is 100 then the value of Fb should be 980 to give us the force of 1080. right? plot the graph like this. you will get the straight line in the other direction , with the positive gradient

 

[Studydayandnight]

880 + 200 gives us 1080
upward should be equal to downward forces for the plank to be in equlibrium
so we want 1080 upward force. now look athe graph , when the value of FA is 100 then the value of Fb should be 980 to give us the force of 1080. right? plot the graph like this. you will get the straight line in the other direction , with the positive gradient

Thank you so much!

Also, for this question, To find the total EMF, why are we subtracting 12 from 20? Shouldn't we be adding to find the total emf? :s

and for part (ii) , why can't I use the formula P=V2/R to find the power of G?