GCSE Physics P3 - 24/05/2012

Hey, there wasn't any thread around so i made a new one.

Are you guys ready for the P3 physics exam, and what are the main things which we should revise? And what might be coming up? :wink:

(edited 11 years ago)

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Reply 1

sophieking

You should revise everything from the P3 topics..anything could come up. However, look at the past papers and see what type of questions normally appear and look at the mark schemes to see how to answer them. I'm also sitting this exam and I am so scared :confused:

Good luck!

Reply 2

natnalie

anyone have any useful notes about pulse oximetry?

Reply 3

hypanx

does anyone know what formulas we need to learn (not the ones providd)?

Reply 4

Coveted Ul

Memorize:

1). P=m X v (incase, there hasn't been a momentum question in the past papers, so they might put one in)

And

2. Current (I) = (n X e) / t

n - number of electrons
e - charge of electrons
t - time (in seconds)

The rest will be given to you.

Reply 5

Frontierlandwdw

Any one got any good points/notes on electron beams?
Would be so grateful!! :biggrin:

Reply 6

lettucesoap

I found a great set of online flashcards on p3 which definately helps. http://quizlet.com/12255177/edexcel-p3-flash-cards/ :biggrin:

Reply 7

hypanx

Original post by Coveted Ul

thanks.. what does the P stand for though (sorry physics isn't my best subject :s-smilie:

Reply 8

Coveted Ul

P - is momentum (in kg m/s)

Reply 9

nervouspupil123

does anybody know how to tell when the source required needs a short half life or not?

Reply 10

Katy1704

Yeah the source needs a short half life when it is a tracer because it is inside the body so can damage healthy cells, but if the source is being used in radiotherapy as a treatment then a longer half life is more practical or hospitals would have to contsantly replace the radioactive sources. I hope this helps.

Reply 11

Katy1704

Can somebody please help me with endoscopy because I'm finding it hard to get it in my head in short little steps - the book is really confusing me HaHa xD

Reply 12

Katy1704

Original post by hypanx

thanks.. what does the P stand for though (sorry physics isn't my best subject :s-smilie:

Sorry having a really stupid moment here but what does the m and the v stand for in the P=m X v equation? Is it mass and voltage?

Reply 13

lettucesoap

Original post by Katy1704

Sorry having a really stupid moment here but what does the m and the v stand for in the P=m X v equation? Is it mass and voltage?

nearly there - m = mass and v = velocity

so momentum = mass / velocity

Reply 14

lettucesoap

Original post by Katy1704

Can somebody please help me with endoscopy because I'm finding it hard to get it in my head in short little steps - the book is really confusing me HaHa xD

it took a long time for me to understand too, dont worry.

so endoscopy is when thin, thin optical fibres are inserted into the body to take a look at tumours, joints etc. whats so special about endoscopy is that fact that it uses total internal reflection to channel light INSIDE the body so that the doctors can actually see what's going on in there. otherwise, it would be pitch black, right?
there are two wires involved - one is used to channel the light via total internal reflection and the other is a camera which displays whats going on inside the screen.

so

1) the light reflects internally through 1 set of optical fibres, reflected repeatedly until they come out at the end.
2) the light is reflected off the objects inside the body which is of interest (kidney stones, tumours etc)
3) camera records whats going on and sends it back up to the doctor.

I've seen past paper questions where they ask the reasons as to why endoscopy is better than open surgery. well..

1) endoscopy is known as keyhole surgery, which as the title suggests, only cuts a little hole in the body. I would prefer a tiny hole compared to having my insides dissected apart, wouldn't you?
2) it's quicker
3) it's easier to do checkups and moniter progress as it can be done more often than open surgery, for obvious reasons.
4) the recovery time is dramatically smaller.

any questions, let me know. hope i helped