AQA Physics PHYA4 - 20th June 2016 [Exam Discussion Thread]

hi has anyone got any summarised notes?

Reply 1042

McDerdactyl

9

Original post by beggelton

Do we need fleming's right hand rule
help me i'm going to fail

same I've lost all hope

Reply 1043

lucabrasi98

15

Original post by ombtom

You must've missed a question. I'm sure I did that this morning.

I genuienly haven't had to use it. It came up in a single question and you didn't even have to use the equation. I used the gradient of the graph and got 3 marks.

I'm worried now because I've never used the equation before

(edited 7 years ago)

Reply 1044

rxns_00

15

Original post by philo-jitsu

I had the same questions...I came to the conclusion it is being dumbed down because it's a levels....because realistically kinetic energy would only be gained from highest point down to equilibrium....everything else is conversion of elastic to grav potential

I think you just assume on the way up its elastic-kinetic, past equilibrium it's Ke to ge...it's dum I know but this way of thinking is what's in the Merck schemes

Original post by Terminatoring

Okay so you've lost energy. SO HOW IS THE TOTAL POTENTJAL ENEGY MAXIMUM.?

It's not really dumbed down, it's just a way of representing energy transfer. A 0GPE level used in M2 which is a maths module and mechanics in maths is more detailed than physics.

I'm not sure you're understanding the idea that it is all RELATIVE.

Imagine we set 0 GPE level which the total potential of the system is 60J (random number ok).
Therefore were pretending that:
0 -> 60J
Therefore if your graph shows that after t seconds, GPE is then -10.
-10 -> 50J
Therefore the negative sign means you've LOST 10J of energy
If your graph shows that after another 2t seconds the GPE is 10
10 -> 70J
Positive sign meaning the system has GAINED energy relative to initial position

Reply 1045

rxns_00

15

Original post by beggelton

Do we need fleming's right hand rule
help me i'm going to fail

Left hand rule -> magnetic fields
Right hand rule -> electromagnetic induction

Reply 1046

https://60abffc9b401b1c0936e01291c15112cab0778c4.googledrive.com/host/0B1ZiqBksUHNYVFI1YlJBOWhwRW8/January%202012%20QP%20-%20Unit%204B%20AQA%20Physics.pdf

In this question the mark scheme says the field lines should point down. But the top plate is stronger, so why shouldnt it point upwards??

Reply 1047

alevelstresss

Original post by Ultracrepidarian

hi has anyone got any summarised notes?

you can see my notes if you want

https://www.dropbox.com/s/s4zgakd11hjczjx/PHYA4%20-%20notes%20REVIEW.docx?dl=0

Reply 1048

alevelstresss

Original post by boyyo

https://60abffc9b401b1c0936e01291c15112cab0778c4.googledrive.com/host/0B1ZiqBksUHNYVFI1YlJBOWhwRW8/January%202012%20QP%20-%20Unit%204B%20AQA%20Physics.pdf

In this question the mark scheme says the field lines should point down. But the top plate is stronger, so why shouldnt it point upwards??

electric field lines are in the direction of +ve to -ve, so its going from the more positive plate to the less positive plate.

Reply 1049

TheLifelessRobot

7

Original post by boyyo

https://60abffc9b401b1c0936e01291c15112cab0778c4.googledrive.com/host/0B1ZiqBksUHNYVFI1YlJBOWhwRW8/January%202012%20QP%20-%20Unit%204B%20AQA%20Physics.pdf

In this question the mark scheme says the field lines should point down. But the top plate is stronger, so why shouldnt it point upwards??

The direction of the electric field dictates where a positive test charge would go. A positive test charge would be more repelled more strongly by the +3V plate than the weaker +1V positive plate so the direction would be down.

Reply 1050

d14m

Original post by alevelstresss

electric field lines are in the direction of +ve to -ve, so its going from the more positive plate to the less positive plate.

The field lines show the path a positively charged particle would take, a positive particle will move to the more negative electrode

Reply 1051

Ultracrepidarian

Original post by alevelstresss

you can see my notes if you want

https://www.dropbox.com/s/s4zgakd11hjczjx/PHYA4%20-%20notes%20REVIEW.docx?dl=0

great thanks

Reply 1052

Original post by TheLifelessRobot

The direction of the electric field dictates where a positive test charge would go. A positive test charge would be more repelled more strongly by the +3V plate than the weaker +1V positive plate so the direction would be down.

Original post by alevelstresss

electric field lines are in the direction of +ve to -ve, so its going from the more positive plate to the less positive plate.

ahh fs ofcourse, thanks guys

Reply 1053

SirRaza97

7

Original post by boyyo

https://60abffc9b401b1c0936e01291c15112cab0778c4.googledrive.com/host/0B1ZiqBksUHNYVFI1YlJBOWhwRW8/January%202012%20QP%20-%20Unit%204B%20AQA%20Physics.pdf

In this question the mark scheme says the field lines should point down. But the top plate is stronger, so why shouldnt it point upwards??

electic field goes positive to negative

Reply 1054

TheLifelessRobot

7

Original post by alevelstresss

you can see my notes if you want

https://www.dropbox.com/s/s4zgakd11hjczjx/PHYA4%20-%20notes%20REVIEW.docx?dl=0

Great notes!

Reply 1055

for the current graoh for capacitor, does it start from from the y axis(i0), or is it an asymptope

Reply 1056

C0balt

16

I feel like I'm ****ed but looking through physics&maths tutor questions I've done them all at some point over the year so I'm okay. I'm okay. C0balt, you're okay. Yeah, I am okay. Calm the **** down.

Reply 1057

OldMathsAccount

Original post by boyyo

for the current graoh for capacitor, does it start from from the y axis(i0), or is it an asymptope

It has to have an initial value, it starts from this value I₀ on the y axis.

Reply 1058