** HL Physics Before / after **

D_s

P=IsquaredR isn't in tables, neither is W=VI (For power cables), that's 2 off the top of my head anyway

MarieCurie22

http://www.thephysicsteacher.ie/leavingcertphysicsrevision.html

Try here!? Idk you might find something there

D_s

Lambda = 4(l+0.3d) is a must to learn off.

xJEx

LCStudent - if you have the marking scheme for the mock paper do you have the answers to the SHM calculation please? (Q6)

Leaving Cert Student

D_s wrote: »

Lambda = 4(l+0.3d) is a must to learn off.

For this exp. do you apply the c=f(lambda) formula afterwards? And do you take the average of all teh values of speed of sound after doing this?

Leaving Cert Student

xJEx wrote: »

LCStudent - if you have the marking scheme for the mock paper do you have the answers to the SHM calculation please? (Q6)

Question 6.
• a = −ω 2s (4m)
Explain notation (2m)
• Hookes law: F = −ks (4m)
Explain notation (2m)
• F = −ks (3m)
F ma a F ks
m m
= ∴ = = − (3m)
as a 2s then 2 k
m
= −ω ϖ = (3m)
as T 2 then T 2 m
k
π π
ω
= = (3m)
• (i) – 10 : 20→4 : 40 = 6 h 20 min (3m)
– 6 20 min 1 period
2
h =
– ∴ Period = 45600 s (3m)
– Amplitude 25 12 6.5
2
= − = m (3m)
(ii) 4 : 40 1
4
+ period (3m)
4 : 40 + 3 h10 min = 7.50 p.m. (3m)
(iii) From above a =ω 2s ∴F = mω 2s (3m)
( )20,000 1.378×10−4 2 6.5 = 2.468×10−3 N (3m)
(iv) F = mω 2s ( )∴1×10−3 = 20,000 1.378×10−4 2 s
∴s = 2.6331m (2m)
– Equilibrium position 25 12 13.5
2
= + = m (2m)
– 13⋅5+ 2⋅63 =16⋅13 m (2m)
13⋅5− 2⋅63 =10⋅87 m (2m)
– Simple pendulum … etc.

D_s

Leaving Cert Student wrote: »

For this exp. do you apply the c=f(lambda) formula afterwards? And do you take the average of all teh values of speed of sound after doing this?

Yes and Yes

xJEx

Leaving Cert Student wrote: »

Question 6.
• a = −ω 2s (4m)
Explain notation (2m)
• Hookes law: F = −ks (4m)
Explain notation (2m)
• F = −ks (3m)
F ma a F ks
m m
= ∴ = = − (3m)
as a 2s then 2 k
m
= −ω ϖ = (3m)
as T 2 then T 2 m
k
π π
ω
= = (3m)
• (i) – 10 : 20→4 : 40 = 6 h 20 min (3m)
– 6 20 min 1 period
2
h =
– ∴ Period = 45600 s (3m)
– Amplitude 25 12 6.5
2
= − = m (3m)
(ii) 4 : 40 1
4
+ period (3m)
4 : 40 + 3 h10 min = 7.50 p.m. (3m)
(iii) From above a =ω 2s ∴F = mω 2s (3m)
( )20,000 1.378×10−4 2 6.5 = 2.468×10−3 N (3m)
(iv) F = mω 2s ( )∴1×10−3 = 20,000 1.378×10−4 2 s
∴s = 2.6331m (2m)
– Equilibrium position 25 12 13.5
2
= + = m (2m)
– 13⋅5+ 2⋅63 =16⋅13 m (2m)
13⋅5− 2⋅63 =10⋅87 m (2m)
– Simple pendulum … etc.

Thank you dude!

MarieCurie22

http://thatsmadthatis.podomatic.com/entry/2009-03-16T08_39_11-07_00

physics definitions !

cremeeggeater

Thinking of dropping to ordinary since it's my 7th subject and I failed the mock, anyone any idea for what I need to know for pass?

Copper_pipe

What experiments do ye predict lads?

Leaving Cert Student

Copper_pipe wrote: »

What experiments do ye predict lads?

Resistivity, moments and specific latent heat of fusion of ice

YoursSincerely

Leaving Cert Student wrote: »

Resistivity, moments and specific latent heat of fusion of ice

All those plus snells law

mulciber

Hey guys, I have a question:

Our teacher never did Hooks law/Simple harmonic motion or Electromagnetism with us. Am I screwed? =/

no scope codgod

One question they seem somewhat fond of asking is about sweat and how it cools you down when you exercise because it takes heat from your body to overcome the latent heat needed to cause evaporation. Can anyone explain how this happens? If heat can only flow from hot to cold how does a body get hot enough to cause evaporation at 100 degrees?

xJEx

mulciber wrote: »

Hey guys, I have a question:

Our teacher never did Hooks law/Simple harmonic motion or Electromagnetism with us. Am I screwed? =/

A lot of people avoid SHM and Hooke's anyway cause they find it difficult so no for that.. but do you mean you didn't do magnets at all?

Leaving Cert Student

You can avoid getting deep in mechanics, magnets and electricity provided you know the basics and experiments and everything else really well

Leaving Cert Student

no scope codgod wrote: »

One question they seem somewhat fond of asking is about sweat and how it cools you down when you exercise because it takes heat from your body to overcome the latent heat needed to cause evaporation. Can anyone explain how this happens? If heat can only flow from hot to cold how does a body get hot enough to cause evaporation at 100 degrees?

Evaporation doesn't have to occur at 100 degrees.

mulciber

Well, we did the thing where you can see a magnetic field by creating a p.d. with to bits of metal and some oil. We never did rotating coils, flux or any of that though. None of the electromagnetism stuff in the book "investigating Physics". =/

xJEx

no scope codgod wrote: »

One question they seem somewhat fond of asking is about sweat and how it cools you down when you exercise because it takes heat from your body to overcome the latent heat needed to cause evaporation. Can anyone explain how this happens? If heat can only flow from hot to cold how does a body get hot enough to cause evaporation at 100 degrees?

I love these type of questions :P It's not quite 100 degrees and don't think of it in terms of that. Basically - the latent heat is needed for a change of state - the body supplies the heat - body cools down. thats all youre gonna need to say

xJEx

mulciber wrote: »

Well, we did the thing where you can see a magnetic field by creating a p.d. with to bits of metal and some oil. We never did rotating coils and stuff though. =/

Do you have the Essentials Unfolded by any chance?

mulciber

xJEx wrote: »

Do you have the Essentials Unfolded by any chance?

No, sorry. But I do have the less stress more success book.

decisions

Experiments:
1. G by free fall/ coplaner forces
2. Heat
3. Snells Law / Speed of sound
4. Resistivity of wire

6. Planetary Motion / SHM
7. Waves, Doppler ect
8. Capacitance, Coulombs Law
9. Photoelectric emission, X rays
10. Cockcroft and Walton experiment
11. ?
12. Electromagnitism, Semi conductor, refractive index (optical fibers?)

Anybody else got any predictions?

MarieCurie22

decisions wrote: »

Experiments:
1. G by free fall/ coplaner forces
2. Heat
3. Snells Law / Speed of sound
4. Resistivity of wire

6. Planetary Motion / SHM
7. Waves, Doppler ect
8. Capacitance, Coulombs Law
9. Photoelectric emission, X rays
10. Cockcroft and Walton experiment
11. ?
12. Electromagnitism, Semi conductor, refractive index (optical fibers?)

Planetary motion was there last year no? And SHM also came up recently Id say forces of motion and uvast....

xJEx

mulciber wrote: »

No, sorry. But I do have the less stress more success book.

Oh cause I was gonna say you can get a good grasp from reading the ike 5 pages in that book. I'd advise doing a few Qs in the papers now and see how you get on, look over the most common definitions, like Faraday's Law, and then that with your basic understanding of the topic will be grand - it's just in case a little something comes up in Q5 if you like that Q or if you you get unlucky and need it to fall back on in a long question

when I say do a few Qs in papers I mean calculations

carlos123455

no scope codgod wrote: »

One question they seem somewhat fond of asking is about sweat and how it cools you down when you exercise because it takes heat from your body to overcome the latent heat needed to cause evaporation. Can anyone explain how this happens? If heat can only flow from hot to cold how does a body get hot enough to cause evaporation at 100 degrees?

You don't need 100 degrees to evaporate water, evaporating and boiling are two different things, our teacher explained it to us by clothes drying on a line, you don't get 100 degrees from the sun yet the water evaporates from the clothes.. Get it? :P

mulciber

xJEx wrote: »

Oh cause I was gonna say you can get a good grasp from reading the ike 5 pages in that book. I'd advise doing a few Qs in the papers now and see how you get on, look over the most common definitions, like Faraday's Law, and then that with your basic understanding of the topic will be grand - it's just in case a little something comes up in Q5 if you like that Q or if you you get unlucky and need it to fall back on in a long question

Ok, I'll do that. Thanks for the help.

mulciber

MarieCurie22 wrote: »

Planetary motion was there last year no? And SHM also came up recently Id say forces of motion and uvast....

I hope that you're right. I love uvast questions. :P

decisions

MarieCurie22 wrote: »

Planetary motion was there last year no? And SHM also came up recently Id say forces of motion and uvast....

It did kinda come up, but it was really a vertical motion q.

mulciber

decisions wrote: »

It did kinda come up, but it was really a vertical motion q.

Looking at the pattern now I would guess that Newton's laws, momentum or density and pressure will come up. I really don't want a SHM question. If that comes up I'm screwed. =/