Physics Help HERE ONLY !!

[Shogun]

alright this depends on the size of gap and size of wavelength,this whole thing is known as diffraction

if size of gap is the same size of wavelength (u gotta measure them with ure scale or the giv u this info on the question): the wave will pass through the gap with a circular pattern.

if size of gap is bigger than the wavelength of the wave: the wave should pass throught in a wide wave around the ages pattern.

it would go like this:
but be sure tht ure wave (outside the gap) must have the dame wave legnth as the wave before the gap, cuz wave length doesnot change , speed does not change, frequency does not change, only direction changes

hope his helps..

[Friends]

ok its simple

when water waves pass thru a gap, if the gap's length is equal to the wave's wavelength then there will b a spherical diffraction,
but if the wavelength of the wave is lower than the gap of the length then the waves formed will hav defraction on their extreme edges, they will look like straight lines that are bent on the edges.

we don't hav the diffraction of waves such that the length of the gap is smaller than the length of the wavelength.

remember the top two points all the best

Ok I got it.thanx man
+rep


Thanx Shogun

[Ibiza279]

guys i was taught there are two types of sound graphs u need to know

one is displacement/time   and the other is displacement/lenth.

can anyone elaborate more about these two types of graphs.

hey call them speed/time and distance/time graph, thats much more easier to understand

as fer the speed time graph, area under the graph gives u the distance travelled.

the distance time graph jus tells u if the cars on constant speed or accelerating etc.

i guess thats all about it.

but be sure to memorise the three velocity formulas

they r

v=u+at

v^2=u^2 + 2as

s = ut + 1/2at^2

where " s " is the displacement

do counter check with ur books or online sources if they r correct lol

[esso]

can any one give me notes about radiation....
a bit difficult...
thanx in advance

[Ibiza279]

wat ever u don't knw bout radiation, ask us here n we ll help

[Shogun]

yea esso anythin in radiations u want do ask..

[idol2009]

Since no one answered my question before, i will repost it =)
 Hey, I was doing the Oct/Nov 08 Paper 3, and on question 5c), it asks you to calculate the specific latent hear of fusion of ice from the results they have given you...
I usually find this pretty straightforward, but on this problem I was kind of stuck, because my answer didn't match the mark scheme...
The question goes as follows:
"Using a 40W heater, 16.3 g of ice is melted in 2.0 minutes. The heater is then switched off. In a further 2.0 minutes, 2.1 g of ice is melted.
Calculate the specific latent heat of fusion of ice from these results."

So I basically did the following calculation:
Total Energy supplied = 40 x 120 = 4800 J
Total Mass melted by heater = 16.3 g
Specific latent heat = 4800/16.3 = 294.5 J/g

I don't understand what I've done wrong, and what the switching the heater off and the further 2 mins has to do with it?
Any help would be appreciated thanks!

[VIP_93]

thanx alot Q80BOY

[Enia]

Hi! I had another tiny question (and probably a lot more as I do last minute revision so plz be patient with me).

Can you please explain to be how to predict the direction of alpha, Beta, and gamma radiations in a magnetic field? Thank you

[Shogun]

Since no one answered my question before, i will repost it =)
 Hey, I was doing the Oct/Nov 08 Paper 3, and on question 5c), it asks you to calculate the specific latent hear of fusion of ice from the results they have given you...
I usually find this pretty straightforward, but on this problem I was kind of stuck, because my answer didn't match the mark scheme...
The question goes as follows:
"Using a 40W heater, 16.3 g of ice is melted in 2.0 minutes. The heater is then switched off. In a further 2.0 minutes, 2.1 g of ice is melted.
Calculate the specific latent heat of fusion of ice from these results."

So I basically did the following calculation:
Total Energy supplied = 40 x 120 = 4800 J
Total Mass melted by heater = 16.3 g
Specific latent heat = 4800/16.3 = 294.5 J/g

I don't understand what I've done wrong, and what the switching the heater off and the further 2 mins has to do with it?
Any help would be appreciated thanks!

oh sorry for u answer to be delayed, so ill try to help u out right away..

[IGSTUDENT]

Since no one answered my question before, i will repost it =)
 Hey, I was doing the Oct/Nov 08 Paper 3, and on question 5c), it asks you to calculate the specific latent hear of fusion of ice from the results they have given you...
I usually find this pretty straightforward, but on this problem I was kind of stuck, because my answer didn't match the mark scheme...
The question goes as follows:
"Using a 40W heater, 16.3 g of ice is melted in 2.0 minutes. The heater is then switched off. In a further 2.0 minutes, 2.1 g of ice is melted.
Calculate the specific latent heat of fusion of ice from these results."

So I basically did the following calculation:
Total Energy supplied = 40 x 120 = 4800 J
Total Mass melted by heater = 16.3 g
Specific latent heat = 4800/16.3 = 294.5 J/g

I don't understand what I've done wrong, and what the switching the heater off and the further 2 mins has to do with it?
Any help would be appreciated thanks!

oh sorry for u answer to be delayed, so ill try to help u out right away..

SHOGUN

R u a student or a teacher? U seem to have an answer for every problem.And time to solve every query

[Ibiza279]

Since no one answered my question before, i will repost it =)
 Hey, I was doing the Oct/Nov 08 Paper 3, and on question 5c), it asks you to calculate the specific latent hear of fusion of ice from the results they have given you...
I usually find this pretty straightforward, but on this problem I was kind of stuck, because my answer didn't match the mark scheme...
The question goes as follows:
"Using a 40W heater, 16.3 g of ice is melted in 2.0 minutes. The heater is then switched off. In a further 2.0 minutes, 2.1 g of ice is melted.
Calculate the specific latent heat of fusion of ice from these results."

So I basically did the following calculation:
Total Energy supplied = 40 x 120 = 4800 J
Total Mass melted by heater = 16.3 g
Specific latent heat = 4800/16.3 = 294.5 J/g

I don't understand what I've done wrong, and what the switching the heater off and the further 2 mins has to do with it?
Any help would be appreciated thanks!

what answer does the mark scheme tell u ?

[Shogun]

Hi! I had another tiny question (and probably a lot more as I do last minute revision so plz be patient with me).

Can you please explain to be how to predict the direction of alpha, Beta, and gamma radiations in a magnetic field? Thank you

deflections of rays in magnetic fields
alpha is positively charged so in magnetic field in to the paper (the north pole faced towards a paper) (uding flemings left hand u point ure index finger just like the way u would point at somone and with the thumb up and ure middle finger pointing towards the right(which is the direction alpha rays)) so doing this would indicate tht alpha rays deflects upwards.
however the beta rays(negatively charges) moves opposite to the deflection of alpha rays (i.e downwards but with the same conditions set as experssed for the alpha rays)
whereas in gamma rays, no deflection in magntic field.

deflections of rays in an electrical field.
lets say there are 2 charged plates place over another(with gap inbetwwen), one is postively charged plate which is for example the upper plate, and the lower plate is negatively charged. alpha rays deflect yowards the negative side (i.e downwards) as it is postively charged, whereas the beta rays deflects towards the positively charge plate(i.e upwards, just opposite of alpha rays). gamma rays do not deflect in electric fields either.

hope this helped, any confusion difficulties or help needed, plz do ask me

[Ibiza279]

Since no one answered my question before, i will repost it =)
 Hey, I was doing the Oct/Nov 08 Paper 3, and on question 5c), it asks you to calculate the specific latent hear of fusion of ice from the results they have given you...
I usually find this pretty straightforward, but on this problem I was kind of stuck, because my answer didn't match the mark scheme...
The question goes as follows:
"Using a 40W heater, 16.3 g of ice is melted in 2.0 minutes. The heater is then switched off. In a further 2.0 minutes, 2.1 g of ice is melted.
Calculate the specific latent heat of fusion of ice from these results."

So I basically did the following calculation:
Total Energy supplied = 40 x 120 = 4800 J
Total Mass melted by heater = 16.3 g
Specific latent heat = 4800/16.3 = 294.5 J/g

I don't understand what I've done wrong, and what the switching the heater off and the further 2 mins has to do with it?
Any help would be appreciated thanks!

oh sorry for u answer to be delayed, so ill try to help u out right away..

SHOGUN

R u a student or a teacher? U seem to have an answer for every problem.And time to solve every query

hey who cares atleast he tells us the answer to the questions n clears our doubts i mean if hes a teacher v thnk him, if hes a student we still thnk him
so thnk u shogun

[IGSTUDENT]

Hey Shogun
R u a teacher or a student/
Where are u giving your exams from?