[Killerstorm2]

(Original post by poopypie)
Hey does anyone know what can be concluded if a positron is found to have a mass of 1.8 x 10^-29 kg?

the answer is that it is travelling close to the speed of light. Why??

Because positron is anti particle of electron, therefore its "rest" mass should actually be 9.11x10^-31 kg...since mass here is bigger than rest mass, we can deduce that there has been increment in mass due to relativisitc effect (travelling close to speed of light)

[Alexlol28]

Any predictions of what is going to come up tomorrow?

[Parthenon93]

(Original post by poopypie)
Hey does anyone know what can be concluded if a positron is found to have a mass of 1.8 x 10^-29 kg?

the answer is that it is travelling close to the speed of light. Why??

Positron has mass of electron 9.11 × 10^−31kg.

E = mc^2

To have a change in mass (due to change in energy), particles should be travelling close to the speed of light because c^2 is the constant in the equation.

[iesians]

is unit 4 tomorrow ??! best of luck to everyone giving it !!!

[savouryjesus]

(Original post by iesians)
is unit 4 tomorrow ??! best of luck to everyone giving it !!!

Unit 4 is in 3 hours

[meraphox]

Good luck everyone!


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[meraphox]

Is anyone making a ms for this paper???
Or does anyone have access to It tomorrow so we can all contribute?

Would really appreciate this


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[Abrar_Higuain]

hey guys how waz da exam...my 1 sucked big tym....specially with that Spaceship thing and the vertical velocity derivations...lost more than 24 marks i assume.....um dead.....

[Freddy12345]

well for that question what i did was first times the mass of the propellent by the speed so we got that momentum. Then I tried to think it out, so it was in space and the type of set up was an explosion, so I said that the momentum of the ship and the propellent must = 0. so taking the momentum of the ship as negative then dividing by the mass, I got the answer 8.02m/s so I said the predicition was pretty accurate, but I am not convinced I am right.

[d_94]

God. Shouldn't the June exams be easier than the January ones? :/

[FDR]

I thought it was a very mixed bag. I thought the multiple choice was OK, the first few questions ok, but was a bit thrown off by the 'show this equation is right' questions, and by the vector questions. Hard to tell what I think I got.

[Parthenon93]

Anyone with the June 2011 U5 QP?

[meraphox]

Anyone actually got the unit 4 paper?
I wanna make a ms

Obviously with everyone's participation lol I'm sure I got nowhere near 100%

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[DeadBullyMafiosi]

Didnt like probing the formula of the tan theta question--had to work myself backwards
For that same question the last part--why was the equation wrong?(2 marks) I didnt have time to put anything as I left for the end but didnt have extra time ahhh!

[DeadBullyMafiosi]

Hoping the grade boundaries arnt too high!

[d_94]

I hate Edexcel.

[shaolin1802]

Gotta agree with freddy on the spaceship one, was about momentum, the whole J J Thompson thing was really hard though, I was never taught that, had to derive most of the equations using units aswell, hopefully I'll get SOME marks for it

[sumzy101]

I Hate Thomson! :P

[Killerstorm2]

i found that paper hard mainly because I was scared about unit 4 after Jan, so the pressure was still on...this paper started good and then it just went to some next level, they brought in lot of "new" concepts in,whether its for momentum,vector, induction etc...it might have been a bit easier question than Jan but i think in terms of difficulty to do those "new" concept within that time frame, it was difficult as jan..

[sirage94]

Hopefully Hard Unit 4 = Easier unit 5