Physics: Post your doubts here!

[omg]

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[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

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[Abdul Hanan]

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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?

 

[omg]

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?

Welcome


erm are you sure you posted the right screen shot?

 

[Studydayandnight]

Welcome


erm are you sure you posted the right screen shot?

Nop, Omg, sorry my bad

It's this one.

 

[sasuke474]

Try to ask your lecturer to let you in for at least 1 lesson. Other than that, there's not much you can do for the practical. Just make sure to read the instructions carefully and don't waste marks unnecessarily on careless mistakes like significant figures. Really watch your significant figures. Good luck!

Any rules you might know of working with sig figs? I mean I know the idea but is there something you're likely to confuse in the exams?

 

[Studydayandnight]

So for this question there's a part (iii), which requires us to:

Calculate the current in the battery.

How do we the get the resistance as 2? :s The correct answer is 6 A.

 

[eliyeap]

Any rules you might know of working with sig figs? I mean I know the idea but is there something you're likely to confuse in the exams?

For the practical, make sure you standardize all of the sig fig for the measurements and calculations that you do. For example, you are plotting a graph of resistance against length. The resistance is from the resistors that you alter. The sig fig for these values don't matter because you aren't measuring it. However the length you are measuring, hence the sig fig matter. Then the values for gradient and etc must also have the same sig fig as the length.
If you calculate 2 values each with a different sig fig ( lets say 1 sig fig and 2 sig fig), the resultant value, the sig fig you take the lower one which is 1 sig fig. Good luck!

 

[Sahil Gupta]

could someone draw the vector diagram for 02/M/J/07 question number 4d) please!