** HL Physics Before / after **

ScummyMan

optimus125 wrote: »

I would be willing to bet almost anything in my possession that co-planar forces is coming up tomorrow. KNOW IT PEOPLE.

Good man

Jackobyte

Lads, for the thin metallic conductor, was it a curve or directly proportional? The book always had directly proportional for metallic conductor but when I drew the graph, there seemed to be a small curve in it. Also, the "explain the shape" seemed to hint at a curve as well. I presumed the thin part of it made it similar to a filament bulb(heat produced which increases resistance) and drew it with a curve. Did anyone else do this?

Lukeyy

Well that was slightly less horrific than I imagined. Emphasis on slightly.

janus510

Mechanics was easier than other years i thought, experiments were nice aswell

nunchuks

lads, that was tidy

xJEx

Jackobyte wrote: »

Lads, for the thin metallic conductor, was it a curve or directly proportional? The book always had directly proportional for metallic conductor but when I drew the graph, there seemed to be a small curve in it. Also, the "explain the shape" seemed to hint at a curve as well. I presumed the thin part of it made it similar to a filament bulb(heat produced which increases resistance) and drew it with a curve. Did anyone else do this?

I drew a line of best fit but it wasn't including many points..
What were you supposed to say for how the rheostat changed the voltage?

Kingkumar

yay! was a pretty good paper. Annoyed with myself for making 1 silly mistake... in the particle physics q where it asked to find the velocity of a proton i used the mass of the electron in the calculations:(.
anyway hopefully should get my A1

xJEx

What calculation answers did people get for question 6?

KildareKing

today was a good day

Kingkumar

xJEx wrote: »

I drew a line of best fit but it wasn't including many points..
What were you supposed to say for how the rheostat changed the voltage?

I drew a line of best fit too and said I is proportional to V etc..but i also said the last few points for the graph seem to curving away this might be due to the conductor heating up . Um for the rheostat i think all u had to say was change the resistance which changes the voltage as V= RI. I drew a potentiometer so i said move the moving contact to adjust volatage

Jackobyte

xJEx wrote: »

I drew a line of best fit but it wasn't including many points..
What were you supposed to say for how the rheostat changed the voltage?

Yeah, I spent ages considering drawing a line of best fit, but felt I'd have been forcing it. The fact that they specifically stated it was thin as well seemed that it had some relevance. Like, usually for exam questions, for the line of best fit, connecting the last point to the origin will work but in this case, that left all the other points at one side of the line.

I said something along the lines of, in a metallic conductor, V=IR at a constant temperature. Therefore, by increasing the resistance by making the current flow through more of the potential divider, the voltage would also increase.

Leaving Cert Student

How many marks does one lose for mistakingly assuming pressure was meausured in Pascals and KiloPascals?

optimus125

Man.UnitedLad wrote: »

Good man

Carefully remove the tampon there darling.

That was unreal, absolutely delighted!

mulciber

I thought that fas fairly handy. I totally blanked on some of the definitions though. =P Hopefully I'll get an A or high B.

dorcan

physics just saved my leaving cert. Did anyone else think Q.5 was really different than usual

xJEx

anyone haveanswers for calculation on 5, 6, 9, 10 or 12? :P need some reassurance

Undeadfred

dorcan wrote: »

physics just saved my leaving cert. Did anyone else think Q.5 was really different than usual

Yeah i did. Had no idea what a storage heater was and was very iffy on a lot of the questions

Leaving Cert Student

dorcan wrote: »

physics just saved my leaving cert. Did anyone else think Q.5 was really different than usual

q5 was tough ya what was the principle of storage heater??

Undeadfred

Leaving Cert Student wrote: »

q5 was tough ya what was the principle of storage heater??

looked it up on wikipediea, it appears to be radiation or convection. I was soooo clost to putting down radiation. I put down heat pump instead cause i had no idea what a storage heater was

optimus125

Leaving Cert Student wrote: »

q5 was tough ya what was the principle of storage heater??

I thought question 5 and 6 were both beautiful! Modern and particle physics were pretty much the exact same as previous years as well.

Did anyone who did Q.11 get the formula to be a=-(2Pi/T)^2 . s ?

Copper_pipe

A storage heater takes in energy during the night when electricity is cheaper and slowly releases that energy during the day

Prodigious

Storage heaters are made of bricks of high heat capacity. Heated during the night when electricity is cheaper, and they release heat slowly during the day.

lisheen2308

Undeadfred wrote: »

looked it up on wikipediea, it appears to be radiation or convection. I was soooo clost to putting down radiation. I put down heat pump instead cause i had no idea what a storage heater was

i said it had bricks in it with a high specific heat capacity, these are heated slowly at night when electricity is cheaper. then during the day when they are switched off they give out heat slowly because of there high specific heat capacity, maintaining an even temperature throughout the house!

something to that degree anyway

Leaving Cert Student

optimus125 wrote: »

I thought question 5 and 6 were both beautiful! Modern and particle physics were pretty much the exact same as previous years as well.

Did anyone who did Q.11 get the formula to be a=-2Pi/T . s ?

I got -4pi squared over T squared times s

jamo2oo9

When I came into the exam today this morning, I was genuinely bricking it but now when I finished it, I was so happy. That may be the nicest paper I've come across in Physics. The STS was simply beautiful with plenty of easy marks for everyone to get. Section A was handy enough and had no problems. For the metallic conductor question on the graph, I just explained that the graph contradicts the theory that was given to us on the course. I wouldn't worry much on that part. The mobile phone charger was very straight forward although I couldn't figure how find how much heat energy would be left in 10mins..? Any ideas?

Kingkumar

Leaving Cert Student wrote: »

How many marks does one lose for mistakingly assuming pressure was meausured in Pascals and KiloPascals?

2 marks i would say...cause the question that said name the units was only worth 4. and u shouldnt be penalised again for the same mistake. but anyway what was the pressure measured in atmosphere's? (didnt do this q)

optimus125

Leaving Cert Student wrote: »

I got -4pi squared over T squared times s

Sorry yeah forgot to put in the squared there, yeah that's what I got.

Jabama

For question 7, did anyone know how to find the permittivity of the string?? i just guessed and used mass/length :P

lisheen2308

jamo2oo9 wrote: »

When I came into the exam today this morning, I was genuinely bricking it but now when I finished it, I was so happy. That may be the nicest paper I've come across in Physics. The STS was simply beautiful with plenty of easy marks for everyone to get. Section A was handy enough and had no problems. For the metallic conductor question on the graph, I just explained that the graph contradicts the theory that was given to us on the course. I wouldn't worry much on that part. The mobile phone charger was very straight forward although I couldn't figure how find how much heat energy would be left in 10mins..? Any ideas?

just use formula p=RI^2 t
dont think its in log books tho

jamo2oo9

Ah damn, that was the formula. Shame it wasn't in the log tables. I could've gotten it no problem. Just wasn't sure on what formula could be used. I made an attempt by using P=VI and I divided it by 600 seconds. Not right at all but hopefully I'll get some attempt marks at it..