** HL Physics Before / after **

Leaving Cert Student

God I dont know why I come on here thought I had A1 in the bag now realize I got at least 2 q5's wrong and last bit of q6...

xJEx

no scope codgod wrote: »

It wouldn't have been a straight line the whole way. The book specifies that it is only within this limit that it is directly proportional. As you increase the Current there will be a heating effect, causing the resistance to rise as well. This explains why the graph started to curve slightly toward the higher values for the voltage.

What do you mean? In the book, it's a straight line the whole way. My graph looked the same, as expected.

Cdawg95

Jackobyte wrote: »

Pretty much the same. My mass of the earth came out as 5.95x10^22, but I had carried all nine decimal places of ω up to that point which may have accounted for the difference.

I got 6.5x10^24.... Mass of earth is usually to power of 24 too!

decisions

12 a 8-8cos30 m, 4.58 m/s, i got a = 2000ish and then F = 12585.84N?

magicianz

The line is curved in real life. iirc from my own leaving cert, they do want the line to curve off for the upper ranges due to the increased resistance from the heating effect.

D_s

Cdawg95 wrote: »

I got 6.5x10^24.... Mass of earth is usually to power of 24 too!

Thank god you were the same, these other answers were scaring me! Yeah I got about that also

Jackobyte

Cdawg95 wrote: »

I got 6.5x10^24.... Mass of earth is usually to power of 24 too!

Sorry, meant to say 5.95x10^24. It was definitely to the power of 24.
I added a line saying M=~6x10^24 after as well cause that is the value usually given in papers.

decisions

Jackobyte wrote: »

Sorry, meant to say 5.95x10^24. It was definitely to the power of 24.
I added a line saying M=~6x10^24 after as well cause that is the value usually given in papers.

Mine was to the power of 24 as well, 22 was a typo.

xJEx

12 (b) max image 5th?

Jackobyte

decisions wrote: »

Mine was to the power of 24 as well, 22 was a typo.

A typo I copied! :pac:

decisions

Jackobyte wrote: »

A typo I copied! :pac:

:P

Cdawg95

Jackobyte wrote: »

Sorry, meant to say 5.95x10^24. It was definitely to the power of 24.
I added a line saying M=~6x10^24 after as well cause that is the value usually given in papers.

What formulae did you use for g? I used F=gm then subbed F value into F=Gmm/d^2

Jackobyte

Cdawg95 wrote: »

What formulae did you use for g? I used F=gm then subbed F value into F=Gmm/d^2

The value of g at that height will be lower than 9.8, I used centripetal force, F=mrw^2 and let the resulting answer equal Newton's gravitational formula. Think that is right anyway. Will run through the calculations again now.

Edit: Just checked it again, and got the same answer, ie. 5.95x10^24. I even tried it using F=mg using the gravity value provided in part IV, and still came out the same.

decisions

8 a) did anyone get .2816J?
b) .033 ohms and how do you do (ii)?

Leaving Cert Student

xJEx wrote: »

12 (b) max image 5th?

Did you have to multiply by 2 and add 1?

xJEx

Leaving Cert Student wrote: »

Did you have to multiply by 2 and add 1?

I did do that at first but i rubbed it out when I reread it - it said the highest order image not the maximum number of images

maughantourig

decisions wrote: »

8 a) did anyone get .2816J?
b) .033 ohms and how do you do (ii)?

E=R(I^2)t

E=(.33)(250^2)(10*60)=(big ass number)J

Eurovisionmad

decisions wrote: »

8 a) did anyone get .2816J?
b) .033 ohms and how do you do (ii)?

P=I^2R you sub in the given value for I and your answer for R you then get an answer in Watts which is J s^-1 so for a minute you multiply your answer by 60, is what I did anyway!

xJEx

anyone get 7.33x10^-10 for decay constant in 9? and 6.82x10^12 for N?

dave2610

xJEx wrote: »

anyone get 7.33x10^-10 for decay constant in 9? and 6.82x10^12 for N?

Pretty sure that's exactly what I got.

Copper_pipe

What did ye get for the focal length in q3

decisions

Copper_pipe wrote: »

What did ye get for the focal length in q3

17.something?

Kingkumar

Copper_pipe wrote: »

What did ye get for the focal length in q3

17.9 i think (rounded up to .9 it was like .89 something)

Cdawg95 wrote: »

I got 6.5x10^24.... Mass of earth is usually to power of 24 too!

i got 5.95x10^24. umm what do you guys think will be acceptable range?

EDIT: NOOOOOOO i might have not remembered to include kg as the units

dave2610

Copper_pipe wrote: »

What did ye get for the focal length in q3

.179m I think

amicus

that was by far the easiest physics exam ever I think :P YE 8.b was 0.33 ohms resistance..current 250 so 250squared by 0.33 by 10 by 60..

amicus

D_s wrote: »

Thank god you were the same, these other answers were scaring me! Yeah I got about that also

I got 5.9 ten power of 24..its the exact mass of earth in fact

no scope codgod

Kingkumar wrote: »

17.9 i think (rounded up to .9 it was like .89 something)


i got 5.95x10^24. umm what do you guys think will be acceptable range?

The actual mass of the Earth is 5.97x10^24 so I'd say you're likely within the range

decisions

17.89cm sounds farmiliar.

I got the last part of 8 correct

amicus

121 for tension ?

lisheen2308

amicus wrote: »

121 for tension ?

198N