Physics: Post your doubts here!

[ashcull14]

IGNORE ---------------> = in middle

View attachment 45066

ooh....thnks

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_1.pdf
Q3 and 4

 

[selena]

Is the answer A ??

yes it's A

 

[selena]

Answer is B from my side... But let her answer if it is A or B

Answer is B but I don't know how

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_1.pdf
Q3 and 4

 

[amal sharkawi]

vertical velocity= u cos 45
horizontal velocity = u sin 45
so, initial K.E. : the vertical and horizontal components of kinetic energy = 1/2 m ( u cos 45 ) + 1/2 m ( u sin 45 ) ......... ( 1/2 m v^2 formula )

so, sin 45 = 0.71
....cos 45 = 0.71 ( check them in the calculator )

so they will give the same kinetic energy for both velocities ( horizontally and vertically )

so at the highest point, (theta) = 90 ( for the vertical velocity ) , horizontal velocity doesn't change
so final kinetic energy = 1/2 m ( u cos 90 ) + 1/2 m ( u sin 45 )..................... ( horizontal velocity is constant ) ( cos 90 is 0 )
final kinetic energy = 1/2 m ( u sin 45 ) + 0 only which is half of the initial kinetic energy.

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_1.pdf
Q3 and 4

Q3
answer will be B
A is Z=Y-X
B is Z=X-Y
C is Y+X
D is -X-Y

Q4
Accuracy is when the answer is closer to the true value and here the true value is 9.81
and being precise is having values 'any' values close to each other
They have asked NOT accurate so not A and B
The C values are not close to each other while the D values are

 

[amal sharkawi]

can any one answer this question plz?

 

[ZaqZainab]

View attachment 45091


can any one answer this question plz?

density=mass/volume
total mass will be 3.5*10^-25* 8 for 1 cube
and so Volume=9.2*10^-25 * 8/(9.2*10^3)
this will give the volume cube root the volume will give the the length on 1 side of the CRYSTAL so we divide by 2

 

[Hadi Murtaza]

but its not tomorrow. o_o

Yo, it ain't tomorrow.

Ohh, i meant for chem students shouldnt have posted here

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_1.pdf
9

 

[chishtyguy]

Answer is B but I don't know how

My mistake... Answer is B... It's the cell with which the voltmeter is connected not the resistor... So Emf coming out of the cell and across the 15 ohm resistor is 7.5V... Then by using the formula I=V/R =7.5/15 , we will get .5 A current...

 

[Hadi Murtaza]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_1.pdf
9

q.9

Displacement is distance from starting point regardless of how much da body has travelled.

Distance with direction from 0 to 3 s is (1/2) * 3 * 30 = 45 m

Distance with direction from 3 to 5 is (1/2) * 2 * -20 = -20 m

So final distance from starting point = 45 - 20 = 25 m
Answer: B

 

[Hadi Murtaza]

q.9

Displacement is distance from starting point regardless of how much da body has travelled.

Distance from 0 to 3 s is (1/2) * 3 * 30 = 45 m

Distance from 3 to 5 is (1/2) * 2 * -20 = -20 m

So final distance from starting point = 45 - 20 = 25 m
Answer: B

Der is another way of solving dis too but its slightly more complicated

 

[amal sharkawi]

density=mass/volume
total mass will be 3.5*10^-25* 8 for 1 cube
and so Volume=9.2*10^-25 * 8/(9.2*10^3)
this will give the volume cube root the volume will give the the length on 1 side of the CRYSTAL so we divide by 2

thanx alotb

 

[amal sharkawi]

can any one answer this plz??

 

[saadkhan97]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_12.pdf

QUESTION NUMBER 29

After what time will some portion of the wavefront XY reach point P?

ASAP!

 

[saadkhan97]

ans pls!

 

[amal sharkawi]

any one answer this plz

 

[amal sharkawi]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_12.pdf

QUESTION NUMBER 29

After what time will some portion of the wavefront XY reach point P?

ASAP!

T=wave length/velocity
they are 3 waves so
T=3 wave length/C
THE ANSWER IS (C)