Physics marathon (hsc) (3 Viewers)

freeeeee

Member
Joined
Oct 31, 2011
Messages
282
Gender
Male
HSC
2012
Just some basic 2mark Questions:

1. Explain what is meant by drift velocity
2. Outline the photoelectric effect
 

dawooddaman

Member
Joined
Aug 22, 2011
Messages
182
Gender
Male
HSC
2012
Looks like everyone asleep or studying, last advice this year’s paper will be heavily based on ITI so study hard and GL, hope you all do well but not as well as me =P
 

nerdasdasd

Dont.msg.me.about.english
Joined
Jul 29, 2009
Messages
5,353
Location
A, A
Gender
Male
HSC
2012
Uni Grad
2017
Looks like everyone asleep or studying, last advice this year’s paper will be heavily based on ITI so study hard and GL, hope you all do well but not as well as me =P
What's ITI? Good luck to everyone :)
 

nucgaek

Member
Joined
Oct 5, 2011
Messages
68
Gender
Male
HSC
2012
So was there a definite answer on what we do/don't need for Electromagnetic/Superconductive trains?
 

dawooddaman

Member
Joined
Aug 22, 2011
Messages
182
Gender
Male
HSC
2012
LOL I just finished revising the 4 modules and I completely forgot all of them
 

LlamaBoi

Member
Joined
Oct 23, 2012
Messages
31
Gender
Male
HSC
2012
What was the significance of J.J. Thompson figuring out the charge to mass ratio of the cathode rays (electrons)?
 

lemon1

Member
Joined
Dec 15, 2011
Messages
71
Gender
Female
HSC
2012
What was the significance of J.J. Thompson figuring out the charge to mass ratio of the cathode rays (electrons)?
The significance??? I only know how he did it! lmao, will a significance be understanding cathode rays better...? :p


Looks like everyone asleep or studying, last advice this year’s paper will be heavily based on ITI so study hard and GL, hope you all do well but not as well as me =P
how could you be so sure it's going to be Ideas to implementation heavy?
 

LlamaBoi

Member
Joined
Oct 23, 2012
Messages
31
Gender
Male
HSC
2012
Significance

In some experiments, the charge-to-mass ratio is the only quantity that can be measured directly. Often, the charge can be inferred from theoretical considerations, so that the charge-to-mass ratio provides a way to calculate the mass of a particle.

Often, the charge-to-mass ratio can be determined from observing the deflection of a charged particle in an external magnetic field. The cyclotron equation, combined with other information such as the kinetic energy of the particle, will give the charge-to-mass ratio. One application of this principle is the mass spectrometer. The same principle can be used to extract information in experiments involving the Wilson cloud chamber.

The ratio of electrostatic to gravitational forces between two particles will be proportional to the product of their charge-to-mass ratios.

wikipedia

also, did Thompson turn off the magnetic field or the electric field after balancing them?
after a bit of googling I'm getting alot of different answers :/
 

RishBonjour

Well-Known Member
Joined
Aug 14, 2011
Messages
1,261
Gender
Male
HSC
2012
YAYAYAYAYYAYAYAYAYYAYAYAYAYAYAYAYAYAYYAYAYAYAYYAYAYAYA for physics YAYAYAYAYAYAYAYYAYA

finished motors. time for ideas now!


significance of JJ thompshon--> read it somewhere--> it was used on different metals, all had the same chare to mass ratio--> suggested a common subatomic particle
milikins oil experiment found the charge and mass
led to the development of plum pudding model.
 

Shadowless

Member
Joined
May 3, 2010
Messages
342
Gender
Male
HSC
2012
Thomson manipulated the strengths of both the electric and magnetic field until the beam passed through both fields undetected – they travelled in a straight line (this is known as the velocity selector)

F_B=F_E→qvB=qE→v=E/B

as the electric and magnetic fields can be calculated, then the velocity could also be determined
Thomson then removed the electric field and determined the radius of the circular path travelled by the particles

F_B=F_C→qvB=(mv^2)/r→q/m=v/Br

since v, B and r are all measureable quantities, the charge to mass ratio could easily be found
q/m=1.76×〖10〗^11 C.〖kg〗^(-1)
Thomson found the ratio to be about 1800 times greater than that of a hydrogen ion
from this, because neither charge nor mass could be found, he concluded that:
the charge on cathode rays was 1800 times greater than that of a hydrogen ion; or
the mass of cathode ray particles was 1800 times less than that of a hydrogen ion
from these results, Thomson assumed that the charge on them was similar in size to that on a hydrogen ion and calculated their mass to be 9.11 x 10-31 kg
the charge/mass ratio was the same no matter what material was used for the cathode, suggesting that cathode ray particles are fundamental particles
the velocity of the particles was much less than the speed of light
 
Last edited:

Demise

Member
Joined
Apr 26, 2011
Messages
636
Gender
Male
HSC
2012
I can't wait for this subject to be out of my life.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 3)

Top