*** Leaving Cert PHYSICS 2014 ***

Aspiring

Isitthough? wrote: »

Yeah it is def the hardest derivation:pac:

It seems they're trying to make physics easier aswell to get more people to do it. Compare recent years with many years ago, tis quite obvious. Also the log tables have changed what comes up a lot, no point them asking a lot of things we can pull straight from the log tables.

Isitthough?

Cakes. wrote: »

I'm leaving out the mechanics experiments... I don't have them studied and there far too much effort!

I could probably wing an SHM or Gravity one though if I'm stuck!

Not looking forward to tomorrow... I have the basics but that's about it!

Just read through them lol..Some of them Im able to remember from doing them in class so I get like half marks for them

Aspiring

Isitthough? wrote: »

Are the Q 5's repetitive? like would they ask one question one year and the exact same one another?

I think the Doppler effect has come up a few times there.

Isitthough?

Aspiring wrote: »

It seems they're trying to make physics easier aswell to get more people to do it. Compare recent years with many years ago, tis quite obvious. Also the log tables have changed what comes up a lot, no point them asking a lot of things we can pull straight from the log tables.

Damn those log tables were gonna pass me!:P And I like it easier I think it will attract those that are interested in physics and the way things work but arnt good at maths

RP77

Predictions:Q1 g by freefall, Q2 latent heat/heat capacity, Q3 speed of sound, Q4 joules law, Q6 SHM, Q7 Something from light..possible wavelength of light exp or mirrors, Q8 Magnetism/ EM induction, Q9 Circuits ..maybe wheatstone or capacitors, Q10a Pair production/annihilation, Q11 something from modern physics.

Isitthough?

Aspiring wrote: »

I think the Doppler effect has come up a few times there.

Ty Im expecting to do Q5 but I never do them/practice themhope a optics Q comes up or heat for Q6 and 7

Isitthough?

RP77 wrote: »

Predictions:Q1 g by freefall, Q2 latent heat/heat capacity, Q3 speed of sound, Q4 joules law, Q6 SHM, Q7 Something from light..possible wavelength of light exp or mirrors, Q8 Magnetism/ EM induction, Q9 Circuits ..maybe wheatstone or capacitors, Q10a Pair production/annihilation, Q11 something from modern physics.

Id love that paper

Aspiring

Isitthough? wrote: »

Damn those log tables were gonna pass me!:P And I like it easier I think it will attract those that are interested in physics and the way things work but arnt good at maths

You can still do a lot with the log tables. A lot of question 5 answers can be plugging numbers into formulas in the log tables. Yeah but still it's very heavy on the definition side of things now.

Just noticed SHM hasn't come up in mechanics for a while. Circular motion came up last year and linear the year before so it could be a possibility.

galpal123

Would the diffraction grating derivation be likely seeing as the wavelength of a monochromatic light exp. is due up? It'd be too long/difficult to appear as 7 marks on Q5 either
I think it was actually easier years ago!

Teachm

romanita wrote: »

This might be a long shot, but if anyone who had the examcraft(I think) mock, would ye mind telling me what ye got for Q7 b (i) and (ii).? The heat gained by ice and the whole 30% heat loss part.

Its DEB.
10133J
Mass water 0 .552kg

Isitthough?

Aspiring wrote: »

You can still do a lot with the log tables. A lot of question 5 answers can be plugging numbers into formulas in the log tables. Yeah but still it's very heavy on the definition side of things now.

Just noticed SHM hasn't come up in mechanics for a while. Circular motion came up last year and linear the year before so it could be a possibility.

:eek: Ok ill try looking at that Im a bit pushed for time though Have Accounting 2morrow too and Im doing modern physics atm and I still have to do like 8 more expt.:( Ty for advice It really does help me :pac: I did SHM a while back hopefully it will all just come back to me

RP77

galpal123 wrote: »

Would the diffraction grating derivation be likely seeing as the wavelength of a monochromatic light exp. is due up? It'd be too long/difficult to appear as 7 marks on Q5 either
I think it was actually easier years ago!

If this exp comes up in Sec B then its very likely that the derivation will be asked

galpal123

RP77 wrote: »

If this exp comes up in Sec B then its very likely that the derivation will be asked

Would the experiment not be more likely to come up in Section A? There was a 12b question on wave nature of light in 2013 and a full question in 2012

ejayy

Are yous all leaving out the 4 experiments that came up in last years paper in section A?

Isitthough?

ejayy wrote: »

Are yous all leaving out the 4 experiments that came up in last years paper in section A?

I am they wont come again its never happened

deadpixel

Isitthough? wrote: »

I am they wont come again its never happened

Electricity has been variations of one experiment 3 years in a row which is a little odd. Other than that it'd be very unlikely.

ejayy

Thanks guys

Teachm

Teachm wrote: »

Its DEB.
10133J
Mass water 0 .552kg

Heat gained by ice=heat lost by water and heat lost by jug and heat lost to room
2100x.025x8 and .025x3.3x10 5 and 4180x.025x14

10133J

10133=70%

14475.7=100%
14475.=4180xmx6 + 510 x .2x6
14475.7-612 =25080m
138637

---

25080. = .552kg

ejayy

Thanks guys

deadpixel

Can a graph be asked for the speed of sound in air question? Its in my text book but not listed in the exam paper graph breakdown so I'm not sure. Doesn't seem too complicated anyway just checking.

Lara_15

deadpixel wrote: »

Can a graph be asked for the speed of sound in air question? Its in my text book but not listed in the exam paper graph breakdown so I'm not sure. Doesn't seem too complicated anyway just checking.

I was thinking the same earlier. Its in my book too but not in my reviswise
I just thought because the revisewise is so ****e they might have forgotten it but maybe not

aleatorio

For the measurement of specific heat capacity do we need to know how to do it the electrical way as well as the mechanical way or??

Teachm

aleatorio wrote: »

For the measurement of specific heat capacity do we need to know how to do it the electrical way as well as the mechanical way or??

Both can come up .mechanical 2007 q2.
Energy lost by hot copper =energy gained by water +energy gained by calorimeter
390x.032x78.5=cx.0455x4.5 + 390x.0557x4.5
979.68=.20475c + 97.7535
979.68 - 97.735 = 0.20475c
881.945

---

0.20475
4307.42 J/kg/K
Must write unit other way


If its a joule meter your left hand side of equation will just have a value eg.2345J

EoghanIRL

aleatorio wrote: »

For the measurement of specific heat capacity do we need to know how to do it the electrical way as well as the mechanical way or??

Yes you need to know both . They don't have to give you an option . It's basically the same anyway just different energy source .

aleatorio

EoghanIRL wrote: »

Yes you need to know both . They don't have to give you an option . It's basically the same anyway just different energy source .

Ok, cos the one we learned was the mechanical one, so Ill just learn the electrical too just in case

Daithi MacG

Aspiring wrote: »

The derivation of the diffraction grating formula hasn't come up in a while. Dunno if they'd put it on tho since it's probably the hardest (imo) derivation on the syllabus.

I think it's probably the easiest I think when I draw the diagram it suits me...Getting that Kepler's Law is the hardest for me...I don't know what's going on when I try to do it, I just plug everything in everywhere.

RP77

deadpixel wrote: »

Can a graph be asked for the speed of sound in air question? Its in my text book but not listed in the exam paper graph breakdown so I'm not sure. Doesn't seem too complicated anyway just checking.

Yes there is a chance that the graph could come up for this question. It appeared on one of the mock papers a few years back. Length on y axis versus 1/freq on x axis. The slope gives c, the speed of sound. The y intercept gives a value for -0.3d where d is the internal diameter of the resonance tube. 0.3d is the end correction ( the location of the antinode).

Teachm

RP77 wrote: »

Yes there is a chance that the graph could come up for this question. It appeared on one of the mock papers a few years back. Length on y axis versus 1/freq on x axis. The slope gives c, the speed of sound. The y intercept gives a value for -0.3d where d is the internal diameter of the resonance tube. 0.3d is the end correction ( the location of the antinode).

Is it not lambda on y axis?

plmko

Teachm wrote: »

Is it not lambda on y axis?

Yeah you're correct

deadpixel

Real world physics has l in metres on y-axis vs 1/f (f/hz) Straight line, not through the origin as y-intercept is -.3d as stated above. Slope would be c/4 though from the formula c =4f(l+.3d)
I'd say we're more to just be asked to figure it p
out from the formula if the experiment does come up but good to know just in case.