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Physics Help HERE ONLY !!
IGSTUDENT:
--- Quote from: Shogun on June 03, 2009, 10:18:33 am ---
--- Quote from: idol2009 on June 03, 2009, 10:12:39 am ---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!
--- End quote ---
oh sorry for u answer to be delayed, so ill try to help u out right away.. ;D
--- End quote ---
SHOGUN
R u a student or a teacher? U seem to have an answer for every problem.And time to solve every query 8)
Ibiza279:
--- Quote from: idol2009 on June 03, 2009, 10:12:39 am ---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!
--- End quote ---
what answer does the mark scheme tell u ?
Shogun:
--- Quote from: Enia on June 03, 2009, 10:15:49 am ---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 :D
--- End quote ---
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:
--- Quote from: IGSTUDENT on June 03, 2009, 10:21:26 am ---
--- Quote from: Shogun on June 03, 2009, 10:18:33 am ---
--- Quote from: idol2009 on June 03, 2009, 10:12:39 am ---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!
--- End quote ---
oh sorry for u answer to be delayed, so ill try to help u out right away.. ;D
--- End quote ---
SHOGUN
R u a student or a teacher? U seem to have an answer for every problem.And time to solve every query 8)
--- End quote ---
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?
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