Physics: Post your doubts here!

[Mahad Tarar]

May/June 2016 qp 12 Q.11

The diagram shows a man standing on a platform that is attached to a flexible pipe. Water is
pumped through the pipe so that the man and platform remain at a constant height

The resultant vertical force on the platform is zero. The combined mass of the man and platform
is 96 kg. The mass of water that is discharged vertically downwards from the platform each
second is 40 kg.
What is the speed of the water leaving the platform?
see Image below!!
Can Someone Please Answer this Question with explanation .

 

[Mahad Tarar]

please help me with que no 35

Cannot be option B and D because p.d b/w S and R can only be 10 if p.d b/w Q and S is zero because then ratio will be same. (WheatStone Bridge theory)
Also p.d b/w Q and S is 2V (5V -3V) ..Therefore A should be correct answer..

 

[Shimmery woods]

May/June 2016 qp 12 Q.11

The diagram shows a man standing on a platform that is attached to a flexible pipe. Water is
pumped through the pipe so that the man and platform remain at a constant height

The resultant vertical force on the platform is zero. The combined mass of the man and platform
is 96 kg. The mass of water that is discharged vertically downwards from the platform each
second is 40 kg.
What is the speed of the water leaving the platform?
see Image below!!
Can Someone Please Answer this Question with explanation .

Use the formula F = m/t * (v-u)
applied force = rate of change of mass * change in velocity
96×9.81 = 40 × (V -0)
rearrange it and you will find the answer

 

[furuta]

hello~ can someone please explain/solve questions: 6,9,10,18 & 37 to me, thank you

http://papers.gceguide.com/A Levels/Physics (9702)/9702_s15_qp_12.pdf

 

[Shimmery woods]

help me with que 15 please

 

[Shimmery woods]

que 30 ...i could get to the part mgd/V but why do we multpily it with e ?
F = E×q
m×g = E ×q
m×g = V÷d × q
mgd/V = q ...how do i get the value of n ?

 

[Shimmery woods]

que 37 please.. im getting 0.75 which is not even in the options

 

[Mstudent]

help me with que 15 please

You must realise that this is a uniform block so the centre of mass is right in the center

Hope this helps

 

[Holmes]

You must realise that this is a uniform block so the centre of mass is right in the center

Hope this helps

good shot boy

 

[Mstudent]

good shot boy

Thanks mate!

 

[Holmes]

Can any one EXPLAIN me Q's 16 ,34, 38. Paper link is given below.
http://papers.gceguide.com/A Levels/Physics (9702)/9702_w13_qp_13.pdf
Thanks in Advance.

 

[Mstudent]

q.16

Its to do with the random motion of the atoms and molecules of a substance

Internal energy is defined as the energy associated with the random, disordered motion of molecules.

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/inteng.html

 

[Holmes]

q.16

Its to do with the random motion of the atoms and molecules of a substance

Internal energy is defined as the energy associated with the random, disordered motion of molecules.

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/inteng.html

sorry the link is
http://papers.gceguide.com/A Levels/Physics (9702)/9702_w13_qp_13.pdf

 

[Mstudent]

sorry the link is
http://papers.gceguide.com/A Levels/Physics (9702)/9702_w13_qp_13.pdf

For q.16

You have a train which is moving. It has a resultant force from the engines due to the total resistive force
The resistive force is divided into two types, air resistance and wheel friction. They want to know they ratio of air resistance to wheel friction of the total resistive force at a given time

Hope that helps

 

[amina1300]

Can any one EXPLAIN me Q's 16 ,34, 38. Paper link is given below.
http://papers.gceguide.com/A Levels/Physics (9702)/9702_w13_qp_13.pdf
Thanks in Advance.

Q34
P = I^2 R 4.0=I^2(20)
Current in circuit = 0.45 A
V=Ir = 0.45*20 = 9.0 V
From kirchhoff's 2 law 16= 9+0.45R R= 16

Q38

 

[amina1300]

que 30 ...i could get to the part mgd/V but why do we multpily it with e ?
F = E×q
m×g = E ×q
m×g = V÷d × q
mgd/V = q ...how do i get the value of n ?

You did everything right. you just replace q with n*e

 

[amina1300]

http://papers.gceguide.com/A Levels/Physics (9702)/9702_w16_qp_12.pdf
Q10 20 22 24 26 29 31 37 39 ??

 

[amina1300]

Q10 20 22 24 26 29 31 37 39 ?? PLEASE EXPLAIN!!

http://papers.gceguide.com/A Levels/Physics (9702)/9702_w16_qp_12.pdf

 

[Mstudent]

F

Q10 20 22 24 26 29 31 37 39 ?? PLEASE EXPLAIN!!

http://papers.gceguide.com/A Levels/Physics (9702)/9702_w16_qp_12.pdf

or q.22

The 10kn load is shared by 4 rods , so just divide the 10*10^3 by four and solve to find the young's modulus!

 

[Mstudent]

Q10 20 22 24 26 29 31 37 39 ?? PLEASE EXPLAIN!!

http://papers.gceguide.com/A Levels/Physics (9702)/9702_w16_qp_12.pdf

Y1 will occur again 1/4 lamda later and 1 lamda later