The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

This discussion is now closed.

Check out other Related discussions

OCR Physics A G484 - The Newtonian World - 11th June 2015

Scroll to see replies

Boundaries? Similar to last year? I think 39 was an A and 44 was an A*.
Original post by The Room Student
Nice, we're pretty close, what method did you use?

I think M1 for saying area = mv, then M2 for summing up, maybe M3 for an accuracy mark and then M4 as the final (correct within a range) answer.


Divided it into 2 triangles and 1 rectangle, then counted squares and half squares (big squares)

Posted from TSR Mobile
Original post by Spirande
the mass decreases as ions are ejected i think


i thought it said in the question that the engine CREATES and accelerates xenon ions? so i was confused whether or not that would be the case
Original post by Help_Me_Alex
and the titanium thing 1) was that time taken really small ?
2) Why would it take longer , heat lost to other titanium and surroundings... what else?


Heat flows to other parts of metal?

Posted from TSR Mobile
Original post by Jamesowl
Did anyone get 1.27×10^-5 or something for the spaceship's acceleration?


I got something like that. I used 0 for u and 1 for t and then the acceleraton was equal to the velocity I calculated (?) idk if I did it right at all tbh
Original post by trooken
Heat flows to other parts of metal?

Posted from TSR Mobile


yeah thats 1 reason what about the second?
Original post by JayGreen
I got something like that. I used 0 for u and 1 for t and then the acceleraton was equal to the velocity I calculated (?) idk if I did it right at all tbh

I think I got that
Original post by BrokenS0ulz
I just used the mass of the spacecraft. I don't think F=ma would apply if you counted the decrease in mass due to the ions?


Yeah I just used the mass of the spacecraft as well. Someone was just saying they used the mass of space craft - mass of xeonon which wouldn't work due to the reason you've said .... I think
Ah **** sake. I said kinetic energy was the force instead of momentum

Posted from TSR Mobile
Original post by Help_Me_Alex
yeah thats 1 reason what about the second?

Heat flows to air
HEat flows to surrounding area of metal?
I think the written questions were really weird in this paper.
Does someone normally do an unoffical markscheme?
Original post by a123a
Boundaries? Similar to last year? I think 39 was an A and 44 was an A*.


43 was an A* last year.
Hopefully the grade boundaries are even lower this year :biggrin:
Original post by BrokenS0ulz
I think I got that


Yeah me too.
Original post by trooken
Heat flows to other parts of metal?

Posted from TSR Mobile


Not all the KE goest to heat energy?
Original post by AlexParmenter
The first question threw me off and I think I've done a lot worse than I was hoping :frown:


same - ruined my confidence (end was easier than start)
Original post by BrokenS0ulz
Heat flows to air
HEat flows to surrounding area of metal?


oh i thought they would both be 1.
Original post by Jamesowl
Did anyone get 1.27×10^-5 for the acceleration of the spacesip? It seems too small but then again it is just ions causing it


I got this, but I'm not too sure. As I used the mass of an ion. Can anyone confirm this answer?
Original post by Help_Me_Alex
and the titanium thing 1) was that time taken really small ?
2) Why would it take longer , heat lost to other titanium and surroundings... what else?


1) some heat lost
2) some photons reflect off the metals surface and are not absorbed
Original post by Help_Me_Alex
oh i thought they would both be 1.


I put that and then I said not all of the photon energy will be transferred into thermal energy. Sounds plausible?
I used both and ended up with about 1.5x10^7 Pa which I think is correct. The two containers are connected by a valve which is opened, connecting the containers and increasing the overall volume.

Related discussions

Latest

Trending

Trending

Articles for you