WJEC AS Physics PH2 June 4th 2015

Is someone making an unofficial mark scheme?

Reply 41

I thought the last reaction involved strong force because the up quark number was conserved? hence the large kinetic energy involved (from the high speeds)

Reply 42

SoThisIsStresful

Original post by merrigold

I thought the last reaction involved strong force because the up quark number was conserved? hence the large kinetic energy involved (from the high speeds)

but there weren't just quarks involved so it couldn't be strong....

Reply 43

Original post by SoThisIsStresful

but there weren't just quarks involved so it couldn't be strong....

were there not? :tongue:

oops

Reply 44

anthonystones

i thought the particles in the last question were muons, which are composed of quarks

Reply 45

anthonystones

what did people think the hardest question was? - besides the last one

Reply 46

MariaTheSkater

Wasn't it the one before that was a weak interaction?

I remember the previous one being weak because it had a neutrino but I think the last one was strong.. it was something like: meson + H nucleus -> two protons; so it only involved particles made up of quarks..?!

Posted from TSR Mobile

Reply 47

Original post by MariaTheSkater

Wasn't it the one before that was a weak interaction?

I remember the previous one being weak because it had a neutrino but I think the last one was strong.. it was something like: meson + H nucleus -> two protons; so it only involved particles made up of quarks..?!

Posted from TSR Mobile

that's what I thought! :redface:

Reply 48

avengedabbie

6

Original post by WhisperingTide

Wavelength was 4.8
Velocity can be worked out using other wave. (50*1.6 =80)

Therefore frequency is 80/4.8

Which gave me 16.7Hz or something.

seems so obvious now, knew I needed a velocity just didn't know what numbers to use, silly me!

Reply 49

avengedabbie

6

what percentage did people get in the laser question? think I got 14%

Reply 50

loinducoeur

3

Original post by avengedabbie

what percentage did people get in the laser question? think I got 14%

I think I got something like that. I wasn't really sure which stimulated emission value to use.

Reply 51

somevirtualguy

Original post by loinducoeur

I think I got something like that. I wasn't really sure which stimulated emission value to use.

In four level lasers the stimulated emission normally takes place from Level 3 down to Level 2, and yeah I got 14.7% :smile:

Reply 52

avengedabbie

6

any theories on grade boundaries?

Reply 53

Eddard_Stark

Original post by avengedabbie

any theories on grade boundaries?

100 for an A* probably

Reply 54

PrimeLime

OP

12

Original post by Eddard_Stark

100 for an A* probably

A*? XD
Anyone got 1417 for Stefan and 1413 for Wien? (Obviously you may have slightly different values.) I think I got them right because they're virtually the same?
16.7 Hz for the fundamental (first harmonic) frequency, as someone else got :biggrin:

.
Violet travels more slowly? It fits it with v=f(lambda) as well, so I think it's right.
14.something for laser percentage. :smile:

Repulsion between positive charges, overcome strong force, high kinetic energies, etc. for last question?

Any other questions that are worth discussing? I can't remember many right now.

Oh, and the crests were 1/3 wavelength along, right?

Reply 55

somevirtualguy

Original post by PrimeLime

A*? XD
Anyone got 1417 for Stefan and 1413 for Wien? (Obviously you may have slightly different values.) I think I got them right because they're virtually the same?
16.7 Hz for the fundamental (first harmonic) frequency, as someone else got :biggrin:

.
Violet travels more slowly? It fits it with v=f(lambda) as well, so I think it's right.
14.something for laser percentage. :smile:

Repulsion between positive charges, overcome strong force, high kinetic energies, etc. for last question?

Any other questions that are worth discussing? I can't remember many right now.

Oh, and the crests were 1/3 wavelength along, right?

I got all the same, wasn't sure about the crests so I'm glad someone else did them 1/3 along too :smile:

Really annoyed with myself as I put a strong interaction for the particle question because I saw the small time period, and was completely oblivious to the neutrino :frown:

that's the price you pay for rushing lol

Reply 56

Eddard_Stark

Original post by PrimeLime

A*? XD
Anyone got 1417 for Stefan and 1413 for Wien? (Obviously you may have slightly different values.) I think I got them right because they're virtually the same?
16.7 Hz for the fundamental (first harmonic) frequency, as someone else got :biggrin:

.
Violet travels more slowly? It fits it with v=f(lambda) as well, so I think it's right.
14.something for laser percentage. :smile:

Repulsion between positive charges, overcome strong force, high kinetic energies, etc. for last question?

Any other questions that are worth discussing? I can't remember many right now.

Oh, and the crests were 1/3 wavelength along, right?

I got around 2400 K for both. If anyone remembers the name of the star, we could easily double check though
Got the same as you for the rest of those.

(edited 8 years ago)

Reply 57

Original post by Eddard_Stark

I got around 2400 K for both. If anyone remembers the name of the star, we could easily double check though
Got the same as you for the rest of those.

It was called Aldebaran, I think :smile:

Reply 58

holly30

Yes, it was definitely Aldebaran. I remember the radius being 44.2 times bigger than the sun.
I got something around 3900 and around 4100 for each answer. The actual temperature is 3910K.

And yeah, I also drew my wave crests 1/3 along and my percentage for that laser question was also 14.7%. :smile:

Reply 59