Edexcel A2 Physics Unit 5 &#x27;Physics from Creation to Collapse&#x27;

One Physics exam done, one more to go. Need to start revising for this now.

Reply 81

JayAyy

14

Can't be asked to revsie for Economics. I need to revise for this one more...

Reply 82

omegaSQU4RED

18

I've got a Chemistry exam the day before this, I should probably be doing a lot more revision...

Only phy5 left!

OL1V3R

I've got a Chemistry exam the day before this, I should probably be doing a lot more revision...

Same. Haven't started revision for either of them but i think 10 days is more than enough.

What kind of questions are we expecting to come up? I know its a bit hard to say especially because are no past papers but still.

Reply 85

Oscillations is the topic I find difficult in phy5

Reply 86

samydude

I agree with Pegasus92.

Reply 87

This unit is more now since I have messed up phy4 big time

Reply 88

how was phy4 by the way?. i did good in it the multiple choice questions, but the written was
very bad. The mypobacteria part, the graphs of the ac-dc question with the capacitor and
the particle collision question. I had no idea of the momentum diagram, the rest i think was fine. Just
hope that the grade boundary will be low, In jan 2010 ,A was at 55/80... lets hope this time it is 40/80 :biggrin:

Reply 89

hope for the best and be prepared for the worst

Reply 90

WindsorHL3

Hopefully this one will be easier then unit 4.

Reply 91

how much do you expect in unit 4 , windsor ?

Reply 92

BPat

Can someone please type up the 5 assumptions you make about ideal gases?

I've got two different books mentioning 5 different things.

Reply 93

omegaSQU4RED

18

BPat

Can someone please type up the 5 assumptions you make about ideal gases?

I've got two different books mentioning 5 different things.

Here they are:

- The particles in an ideal gas have no size.
- No force is exerted when particles collide, and they collide elastically.
- The only things the particles collide with are other particles and the walls of the container.
- The particles have only kinetic energy, no potential energy.

That might be all of them, and any more I can remember would probably only be wording these ones in a different way.

Reply 94

BPat

OL1V3R

Here they are:

- The particles in an ideal gas have no size.
- No force is exerted when particles collide, and they collide elastically.
- The only things the particles collide with are other particles and the walls of the container.
- The particles have only kinetic energy, no potential energy.

That might be all of them, and any more I can remember would probably only be wording these ones in a different way.

Thank you. :smile:

The book is saying that collisions obey Newton's law of motion and time spent during collisions is negligible compared to time in free motion.

But i guess it means the same thing, just worded differently.

Reply 95

definite_maybe

Hi

Could someone please explain the experiments we need to know for pV= nRT, or have a link to a website showing set up of apparatus etc

Reply 96

omegaSQU4RED

18

definite_maybe

Hi

Could someone please explain the experiments we need to know for pV= nRT, or have a link to a website showing set up of apparatus etc

Not sure if there area any experiments to that specific equation but I think I remember the experiments for the different ideal gas laws.

Boyle's law - for a gas of constant mass and constant temperature, the pressure of a gas is inversely proportional to its volume.

To illustrate this, just set up a gas supply to a barometer and a measuring tube full of a liquid. If you add small amounts of the gas to the measuring tube, and plot a graph of pressure (read from the barometer) against volume (read from the tube), then it should be a reciprocal graph (i.e. like that of y = 1/x).

Charles' law - for a gas of constant mass and constant pressure, the volume it occupies is directly proportional to its absolute temperature.

To illustrate this, just connect a gas supply to an upturned measuring cylinder which is suspended in a beaker of water, on top of a gauze and just above a Bunsen burner. Add a barometer as well and a thermometer inside the beaker. If you change the flame on the Bunsen burner, and plot a graph of absolute temperature (read off the thermometer, and then added 273 to it to make it in Kelvins) against the volume occupied (read from the amount of gas in the cylinder) and it should be a straight line passing through the origin (with a positive gradient).

Guy-Lussac law - for a gas of constant mass and constant volume, the pressure of the gas is directly proportional to its absolute temperature.

To illustrate this, just use the same apparatus as in demonstrating Charles' law, but replace the upturned measuring cylinder with a spherical flask directly connected to a barometer, and plot a graph of pressure against absolute temperature, it will be a straight line passing through the origin (with a positive gradient).

Reply 97

mtkhusro

how was phy4 by the way?. i did good in it the multiple choice questions, but the written was
very bad. The mypobacteria part, the graphs of the ac-dc question with the capacitor and
the particle collision question. I had no idea of the momentum diagram, the rest i think was fine. Just
hope that the grade boundary will be low, In jan 2010 ,A was at 55/80... lets hope this time it is 40/80 :biggrin:

Hope so, in jan for one chem unit it was 48/80

Reply 98

yeah lets hope so, i just wish that i get a good grade in physics, i already have an A in maths, i am not worried about chemistry, hopefully i will get a B , its just physics that i am bothered about.,,anyways how was your 6ph04 for you? were you comfortable with the questions i mentioned?

Reply 99