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**Physics...Before/After**
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I don't think it has to, but I'd have a flick through it because its really easy. I made loads of notes the other day I could send them to you if you'd like?
That'd actually be class if you could
ATM I'm just finishing learning off the definitions from here but some proper notes would rock!
And yeah, my mind was blown when I found out Lenz's Law was an example of Newton's Third Law too. Pretty cool stuff. The emf inducing the current, and the back emf opposing the emf that produced it, is actually an example of an action-reaction pair. 
Fascinating like1) change in emf 2) change in resistance?
Loving the conciseness of that answer :P Definitely gona write that one down.
Q: What is the photoelectric effect? Give an application of it.0 -
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Dwellingdweller wrote: »Q: What is the photoelectric effect? Give an application of it.
Photoelectric effect is the emission of electrons from the surface of a metal as light of a suitable frequency falls on to it.
Automatic door sensors are an example of the photoelectric effect. 0 -
Dwellingdweller wrote: »I think that's it! The way I think of it is that there's actually two waves travelling around the circuit simultaneously, one negative and one positive, the negative current flows into the N-layer so it doesn't pass through and only the positive current flows through. Full-wave rectification is when the diodes are arranged so the negative gets squeezed into the positive axis and comes out as 'smoothed' (using a capacitor) on the oscilloscope.
Q: How is Lenz's Law an example of Newton's Third Law in Electricity?
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Liveforrugby wrote: »
No harm in testing ye on your general physics knowledge either. It's good to know how these things interact. 0 -
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Lol. No. :L I want to slap the guy who put it up with a robot arm though.Liveforrugby wrote: »Did you get robot arm? 0 -
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Its borderline. Based on the solutions of paper 1 posted. I should have gotten 99% in P1 so if I do get it, I will only get it just. What makes me mad is that i was just about to get the right value for k for the circle question (only had to solve quadratic using -b formula) and thought i was doing it wrong.Liveforrugby wrote: »My thoughts exactly, you think you still might of gotten the A1?
And I mssed up the part a in Q8 by forgetting to subtract 80 from 180 to get beta and messed up the graph at the end by forgetting about the semi circles :S
Hopefully I'll get it. :S0 -
Its borderline. Based on the solutions of paper 1 posted. I should have gotten 99% in P1 so if I do get it, I will only get it just. What makes me mad is that i was just about to get the right value for k for the circle question (only had to solve quadratic using -b formula) and thought i was doing it wrong. And I mssed up the part a in Q8 by forgetting to subtract 80 from 180 to get beta and messed up the graph at the end by forgetting about the semi circles :S
Hopefully I'll get it. :S
Yea I got the 80 for beta, hopefully it's only a blunder... if you got 99 in paper 1 and the circle and bionic arm were the only problems, looks like an A1 to me 0 -
Well it depends if they like my question 7 answers and how much marks I will accumulate in that Q8. My b and c parts were a disaster. If I would have done that triangle, graph and circle question right, I'd be at ease. :SLiveforrugby wrote: »Yea I got the 80 for beta, hopefully it's only a blunder... if you got 99 in paper 1 and the circle and bionic arm were the only problems, looks like an A1 to me
Here's hoping. 0 -
This probably isn't the place but we're taking 3+2root2 to be the value for k right?Well it depends if they like my question 7 answers and how much marks I will accumulate in that Q8. My b and c parts were a disaster. If I would have done that triangle, graph and circle question right, I'd be at ease. :S
Here's hoping.0 -
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Well, hopefully they'll give it to me. I've worked so hard for that bloody A1 that it would kill me a little inside if I didn't get it.Yera, I wouldn't be too worried, figures this year people 1 will be the one that will be defining. The former vice principal of my school is the assistant chief examiner and he said that if you wrote anything at all down for any question the likelihood is that you will get 5 marks upwards! And sure hey, there's bigger fish to fry next Monday!
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Incompetent wrote: »Lads anyone know for the pendulum which goes on which axis?
One book says T^2 goes on x, one says on y
Just had a quick look at that myself. It's l on the y axis and T^2 on the x axis, but it's not obvious at first, so I'll type out how I got to grips with it, hopefully it'll help ya understand it too. Those graphs can be confusing.
So you start with your formula:
T=(2pi)*(sqrt(l/g))
Square both sides
T^2=4(pi^2)*(l/g)
So now you have an equation in the form y=mx+c. c=0 because the graph goes through the origin, so the equation is just y=mx. You need to switch it around to get g.
g=4(pi^2)*(l/t^2)
As you can see l/t^2 is the slope, just multiply 4(pi^2)(slope) to get g. Hope that helped! 0 -
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I'm contemplating not sitting the physics exam AT ALL. I'm so not prepared and I don't get physics at all at all- got a D last year!! I'm seriously panicking and it'll effect accounting (my fav subject) as well, it did last year.
bad idea? And my parents will flip! 0 -
cocopopsxx wrote: »I'm contemplating not sitting the physics exam AT ALL. I'm so not prepared and I don't get physics at all at all- got a D last year!! I'm seriously panicking and it'll effect accounting (my fav subject) as well, it did last year. bad idea? And my parents will flip!
Just sit it, who knows the paper might suit you! Imagine how pissed you'd be if you looked at the paper realising that you could of done well?
Besides, you can always leave a bit early.0 -
cocopopsxx wrote: »I'm contemplating not sitting the physics exam AT ALL. I'm so not prepared and I don't get physics at all at all- got a D last year!! I'm seriously panicking and it'll effect accounting (my fav subject) as well, it did last year. bad idea? And my parents will flip!
Just sit it, who knows the paper might suit you! Imagine how pissed you'd be if you looked at the paper realising that you could of done well?
Besides, you can always leave a bit early.
True, but I act don't know anything except sound,light and heat. And may be a bit of mechanics. And I don't want a D on my report
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Probably better than a NG?cocopopsxx wrote: »True, but I act don't know anything except sound,light and heat. And may be a bit of mechanics. And I don't want a D on my report0 -
It just struck me that pretty much every famous scientist has an equation named after them, so if a question comes up like, "What contribution did so-and-so make to physics?" and I haven't a clue… "Well, er, he developed the 'so-and-so' equation." Worth a shot?cocopopsxx wrote: »I'm contemplating not sitting the physics exam AT ALL. I'm so not prepared and I don't get physics at all at all- got a D last year!! I'm seriously panicking and it'll effect accounting (my fav subject) as well, it did last year.
bad idea? And my parents will flip!
You'll be grand. The equations are in the tables so just pick them up from the tables and write them down on the paper. That's 3 out of 9 marks already. If you're not sure what equation to use then write 5 or 6 on your paper. Then just sub in numbers for letters and hope for the best. As for the definitions, once again, a lot are actually in the tables, i.e. Coulomb's law, the law of gravitation. If your doing honours then ask for the pass paper, that is, if you're not comfortable on the day. Don't worry if you failed the mocks (so did I), the leaving cert paper tends to be easier. A lot of the paper is applications of physics, "State 2 applications of convex lenses"; these are quite guessable. Even if yo do fail, you're not loosing anything compared to not sitting the paper at all. Just go in and do it. Presumably you have 6 other subject so Physics won't even count. Where's the pressure?0 -
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would really like to know this as well.
Just figured out the experiments we don't need at OL.
Mechanics
-Investigation of the relationship between period and length for a simple pendulum and hence calculation of g
Light, Sound and Waves
-Only need one experiment of finding the refractive index of something, so I'm choosing to leave out Finding the refractive index of water
-Investigation of the variation of the fundamental frequency of a stretched string with tension
Heat
-Only need one experiment of measuring specific heat capacity, so I'm leaving out Measurement of the SHC of a metal by electrical method
And all of the electricity experiments are OL as well, but I don't plan on covering any electricity experiments. :P0 -
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