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Physics 9702 Paper 4 Preparation and Sure Questions

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Number 1 : Usually Always About Gravitation (Usually 8 marks)
Formulas to know mainly :
1) w=2 pi / T or 2 pi F
2) F=1/T
3) Fg = GMm/r^2 (point masses)
4) Fc = mrw^2 or mv^2/r
5)gravitational potential = -GM/r
6) Gravitational potential energy = -GMm/r
7) Fc=Fg (gravitational force provides centripetal force)
8) Change in G.P.E = Final G.P.E - Initial G.P.E = -GMm/r1 -(-GMm/r2)
9)K.E = GMm/2r
10) g= F/m = GM/r^2 ( know how to derive)
11) Escape velocity : Using (Change in G.P.E = Change in K.E) (GMm/r = 1/2 mv^2)(Escape velocity= (2GM/r)^1/2) )

Definitions :
Newtons Law of Gravitation : Gravitational force between 2 point masses is directly proportional to the product of the masses and inversely proportional to the square of the distance between them
Gravitational Field : Region of Space in Which a mass experiences a force
Gravitational Field Strength : It is the Gravitational force acting per unit mass
Gravitational Potential : Work done in Moving unit mass from infinity to the point
Geostationary Orbits : 1) Orbit around the equator with a period of 24 hours 2)Object is always at one spot in sky 3)Orbits from West to East

Additional Information :
Gravitational Potential is always negative:
1) Potential at infinity is defined to be zero
2) Gravitational Forces are always attractive
3) Work is got out by moving mass from infinity to the point
Circular orbits : Gravitational Force provides the Centripetal Force
Gravitational potential and Electric Potential : 1) Both involve W.D To bring Unit mass/positive charge from infinity to the point 2) Potential for gravitational always -ve , for Elective can be -ve or +ve

This is Just for topic 1 ..I will be posting the rest soon.. Pls drop down ur comments and feedbacks.
And if anything Pls don't hesitate to ask .
 
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Number 2 depends really but usually question is based on Ideal Gas (Usually 8 marks)
Formulas to know mainly :
1) pV=nRT (take care of S.I units)
2) p=1/3 x (density) x <c^2> = Nm<c^2>/3V
3) K.E = 3/2 kT ( for 1 molecule)
4) K.E = 3/2 NkT (for N molecules)
5) k= R/Na = Boltzmann Constant
6) n= N/Na = m/Ma

Definitions:
Ideal Gas: Gas that obeys ideal gas equation , pV=nRT at all values of p,v and T
Assumptions of kinetic theory (ideal gas) : 1) Particles are in random motion 2)Particles have negligible volume 3) No intermolecular forces between particles 4) Elastic collisions 5) Negligible collision time
<c^2>= Mean square speed of the molecules.
Mole: Amount of substance that contains the same number of particles as that in 0.012 kg of Carbon-12

Additional Info:
Ideal gas had negligible intermolecular forces of attraction and repulsion, hence P.E = 0 , hence Internal energy only depends on K.E and hence absolute Temperature (K.E is directly proportional to Temperature in Kelvin)
Hence when Absolute Temperature is 0K = 0 K.E
Internal energy = Sum of kinetic energy and sum of potential energy of the molecules in a system
Know about BROWNIAN MOTION (Gas molecules moving in random motion.. etc.)

This is the next one.. i will be posting the rest soon, again if any questions pls do ask , and if any comments on notes, pls do say . These are my own notes, and hope it helps everyone.
 
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Can you give me the magnetism notes?
I assume what u r asking on is on ELECTROMAGNETISM
so heres some important notes on that :
Definition
Magnetic Field:
Region of space in which a moving charge experiences a force
Tesla (Based on eqn. F=BIL sinθ )
It is the magnetic flux density of the magnetic when a conductor carrying a current of 1A place perpendicular to the field experiences a force per unit length
Magnetic Flux Density : ( Based on F= BIL sin θ )
It is the magnetic field strength of the magnetic field when a conductor carrying a unit current placed perpendicular to the field experiences a force per unit length.

EQUATIONS : 1) F=BIL sinθ 2) F=Bqv sinθ

Additional information:
-Current Balance:
Increase reading of balance :- Force by wire on the magnet /balance is downwards. By Newtons 3rd Law, force of equal magnitude but opposite direction on the wire hence upwards
Decrease reading of balance:- Force by wire on the magnet/balance is upwards. By Newtons 3rd law , force of equal magnitude but opposite direction on the wire hence downwards.

-Force Between 2 parallel wires:
Current in each with produces a magnetic field
The magnetic field of one wire cuts normally with the current in the other wire
This causes a force on the other wire
By Newtons 3rd law, there is a force on the first wire that is equal in magnitude but opposite in direction to the 2nd wire.

-Force on a moving charge in a magnetic field:
Moving charge in magnetic field causes a force on the charge that is perpendicular to the magnetic field and the movement of the charge
Because the force is perpendicular to B and v , this magnetic force provides the centripetal force causing the charge to move in a circular path

-B-Field patterns: (B-Fields - Depends on moving charge. Perpendicular to the force . Force depends on Speed)
Straight wire: Concentric circles, separation of circles get bigger away from wire
Solenoid : Constant Field inside

-Newtons 3rd law :
-Flemings Left hand rule ( Easy way to remember is F-B-I .. or F-F-C (like K-F-C) )

-Hall probe :
Moving charge in a semiconductor slice perpendicular to B-field causes a force on the charge.
This causes charge to move to one side producing a potential difference between the two sides.
This creates an electric field and force on the moving charges in the opposite direction
When the 2 forces balance, remaining moving charges move undeviated
The potential difference here is called Hall voltage.


Hope this is what u want , and hope it helps,
If any more comments or feedbacks pls do ask
:D
 
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THANK YOU SOO MUCH!!
I might bother you again, these are just amazing!!

I assume what u r asking on is on ELECTROMAGNETISM
so heres some important notes on that :
Definition
Magnetic Field:
Region of space in which a moving charge experiences a force
Tesla (Based on eqn. F=BIL sinθ )
It is the magnetic flux density of the magnetic when a conductor carrying a current of 1A place perpendicular to the field experiences a force per unit length
Magnetic Flux Density : ( Based on F= BIL sin θ )
It is the magnetic field strength of the magnetic field when a conductor carrying a unit current placed perpendicular to the field experiences a force per unit length.

EQUATIONS : 1) F=BIL sinθ 2) F=Bqv sinθ

Additional information:
-Current Balance:
Increase reading of balance :- Force by wire on the magnet /balance is downwards. By Newtons 3rd Law, force of equal magnitude but opposite direction on the wire hence upwards
Decrease reading of balance:- Force by wire on the magnet/balance is upwards. By Newtons 3rd law , force of equal magnitude but opposite direction on the wire hence downwards.

-Force Between 2 parallel wires:
Current in each with produces a magnetic field
The magnetic field of one wire cuts normally with the current in the other wire
This causes a force on the other wire
By Newtons 3rd law, there is a force on the first wire that is equal in magnitude but opposite in direction to the 2nd wire.

-Force on a moving charge in a magnetic field:
Moving charge in magnetic field causes a force on the charge that is perpendicular to the magnetic field and the movement of the charge
Because the force is perpendicular to B and v , this magnetic force provides the centripetal force causing the charge to move in a circular path

-B-Field patterns: (B-Fields - Depends on moving charge. Perpendicular to the force . Force depends on Speed)
Straight wire: Concentric circles, separation of circles get bigger away from wire
Solenoid : Constant Field inside

-Newtons 3rd law :
-Flemings Left hand rule ( Easy way to remember is F-B-I .. or F-F-C (like K-F-C) )

-Hall probe :
Moving charge in a semiconductor slice perpendicular to B-field causes a force on the charge.
This causes charge to move to one side producing a potential difference between the two sides.
This creates an electric field and force on the moving charges in the opposite direction
When the 2 forces balance, remaining moving charges move undeviated
The potential difference here is called Hall voltage.


Hope this is what u want , and hope it helps,
If any more comments or feedbacks pls do ask
:D
 
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NOTES ON OSCILLATION

EQUATIONS:

- a= -(w^2)x (defining equation)
- x=x0 sin(wt) where x0=amplitude(possible solution to SHM equation, no damping)
- f=1/T
- w=2πf = 2π/T
- v=v0cos(wt)
- v= +/-w (x0^2 - x^2)^1/2 (DATA SHEET)
- Ep = 1/2 mw^2x^2
- Ek = 1/2 mw^2(x0^2-x^2) using Ek= 1/2mv^2 & v= +/-w(x0^2 - x^2)^1/2
- Et = 1/2 mw^2 x0^2 : Total E = Max K.E = Max P.E

DEFINTIONS :

SHM
-Motion where the acceleration is directly proportional to the displacement from a fixed point
-Acceleration and Displacement are in opposite directions
-Graph of a against x : straight line through the origin and negative gradient

DAMPING(Damped Oscillations)
-(Oscillations where) there is a loss of energy and hence amplitude of the oscillations
- Due to the presence of forces that constantly opposes its motion/ frictional forces

ADDITIONAL INFORMATION :

- SHM: The equation for any oscillation that is SHM can be expressed in the form a= -(w^2)x

- Free oscillations (e.g. simple pendulum)
- Oscillations at natural frequency without external forces
- When undergoing SHM , energy changes between K.E and P.E

- Damped Oscillations : Introduce resistive forces
- Light Damping (oscillations still present but amplitude decreases exponentially / non-linearly , period about constant)
- Critical Damping :
-Shortest time to reach equilibrium, no oscillation
-Eg. car suspension system

- Forced oscillations :
-Oscillations where external forces act on system
- Resonance : (must be forced oscillation)
-Resonant frequency = natural frequency of the system = driving frequency
-Resonance curve (amplitude vs frequency)
-Increase damping : Peak broader and shorter, shifts to the left
-Uses: Quartz Crystal for timing , production of ultrasound, vibration of water molecules in the
microwave
-Disadvantages: Vibrating bridges due to windy conditions and buildings during earthquakes.

HOPE THIS HELPS U GUYS.. AGAIN IF ANY COMMENTS OR FEEDBACKS , PLS DO SO :D
 
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NOTES ON OSCILLATION

EQUATIONS:

- a= -(w^2)x (defining equation)
- x=x0 sin(wt) where x0=amplitude(possible solution to SHM equation, no damping)
- f=1/T
- w=2πf = 2π/T
- v=v0cos(wt)
- v= +/-w (x0^2 - x^2)^1/2 (DATA SHEET)
- Ep = 1/2 mw^2x^2
- Ek = 1/2 mw^2(x0^2-x^2) using Ek= 1/2mv^2 & v= +/-w(x0^2 - x^2)^1/2
- Et = 1/2 mw^2 x0^2 : Total E = Max K.E = Max P.E

DEFINTIONS :

SHM
-Motion where the acceleration is directly proportional to the displacement from a fixed point
-Acceleration and Displacement are in opposite directions
-Graph of a against x : straight line through the origin and negative gradient

DAMPING(Damped Oscillations)
-(Oscillations where) there is a loss of energy and hence amplitude of the oscillations
- Due to the presence of forces that constantly opposes its motion/ frictional forces

ADDITIONAL INFORMATION :

- SHM: The equation for any oscillation that is SHM can be expressed in the form a= -(w^2)x

- Free oscillations (e.g. simple pendulum)
- Oscillations at natural frequency without external forces
- When undergoing SHM , energy changes between K.E and P.E

- Damped Oscillations : Introduce resistive forces
- Light Damping (oscillations still present but amplitude decreases exponentially / non-linearly , period about constant)
- Critical Damping :
-Shortest time to reach equilibrium, no oscillation
-Eg. car suspension system

- Forced oscillations :
-Oscillations where external forces act on system
- Resonance : (must be forced oscillation)
-Resonant frequency = natural frequency of the system = driving frequency
-Resonance curve (amplitude vs frequency)
-Increase damping : Peak broader and shorter, shifts to the left
-Uses: Quartz Crystal for timing , production of ultrasound, vibration of water molecules in the
microwave
-Disadvantages: Vibrating bridges due to windy conditions and buildings during earthquakes.

HOPE THIS HELPS U GUYS.. AGAIN IF ANY COMMENTS OR FEEDBACKS , PLS DO SO :D
please post more notes on different chaps of p4 phy.magnetism etc.please do so
 
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