Author Topic: ALL PHYSICS DOUBTS - POST HERE !!  (Read 231538 times)

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #195 on: May 07, 2010, 07:04:55 pm »
A laboratory determination of the specific latent heat of vaporisation of water uses a 120W heater to keep water boiling at its boiling point. Water is turned into steam at the rate of 0.050 g/s.
Calculate the value of the specific latent heat of vaporisation obtained from this experiment. Show your working.

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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #196 on: May 07, 2010, 07:17:22 pm »
A laboratory determination of the specific latent heat of vaporisation of water uses a 120W heater to keep water boiling at its boiling point. Water is turned into steam at the rate of 0.050 g/s.
Calculate the value of the specific latent heat of vaporisation obtained from this experiment. Show your working.



P= 120 W
Heat (Q)  =  120 J/s

mass = 0.05 g/s

Q = mL

L=  120/0.05
= 2400 J/g

this should be right..:)

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #197 on: May 07, 2010, 07:37:12 pm »
P= 120 W
Heat (Q)  =  120 J/s

mass = 0.05 g/s

Q = mL

L=  120/0.05
= 2400 J/g

this should be right..:)

Thanks this is the answer in d ms. the thing I was confuse with is when they said: Water is turned into steam at a rate of 0.050 g/s. I thought they meant speed. So I ws wondering how to calculate that. But hw is 0.050 g/s the mass?
"If A equals success, then the formula is:
A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Snake

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #198 on: May 07, 2010, 07:50:47 pm »
Guys what was the transformer formula? Np/Ns=Vp/Vs=Ip/Is?
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #199 on: May 07, 2010, 07:52:18 pm »
see the thing here is, as u said they hav given the "mass" as 0.05g per second .. here i didnt literally mean it as 'mass' .. it was jus for ur understanding u kno..:)

but did u get the concept ??
 / sec cancels out in the equation ..  ;)  

Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #200 on: May 07, 2010, 07:56:19 pm »
Guys what was the transformer formula? Np/Ns=Vp/Vs=Ip/Is?

Vs/Vp  =  Ns/Np

to find the number of turns or voltage .. depending on ques ..

Is/Ip  =  Vp/Vs

to find any one if other three are given ..

also theres another  formula ..

Power (loss) = I2R

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #201 on: May 07, 2010, 09:29:44 pm »
see the thing here is, as u said they hav given the "mass" as 0.05g per second .. here i didnt literally mean it as 'mass' .. it was jus for ur understanding u kno..:)

but did u get the concept ??
 / sec cancels out in the equation ..  ;)  

ooooohhhhhh  i see what you mean. Thanks!  ;D ;)
"If A equals success, then the formula is:
A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Baladya

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #202 on: May 07, 2010, 10:11:30 pm »
Looks like i ran out of cool signatures :|

Offline Malak

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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #204 on: May 07, 2010, 11:07:19 pm »

06 Nov P6 1. c) 7.5 (this one is just estimation .. theres no hard and fast rule or ny formula to determine the answer .. ur answer should obiv. a little less than b) ii)

              3. b) i) is attached ..
                     ii) should be base as less room for any error because safer to take as the pins might be of different sizes or not placed vertically/straight.

03 Nov P6 1 d) for this i had to take help from markscheme because i dont hav a hardcopy ..
                     same estimation part .. V= 32.41  take say 1.41 cm3 as 'missing' part
                     subtract it from V to get ii)
« Last Edit: May 07, 2010, 11:26:03 pm by ~VIN1094~ »

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #205 on: May 08, 2010, 05:55:51 am »
For: http://www.freeexampapers.us/IGCSE/Physics/CIE/2003%20Nov/0625_w03_qp_6.pdf
Q4 a
I know its a kiddy question but for some reason i dont understand what scale to use for the x-axis. If I use 0.5 a/(m/s^2) = 2 units it gets hard to plot the points
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A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Ghost Of Highbury

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #206 on: May 08, 2010, 06:30:17 am »
y-axis : 5 units = 0.25

x-axis : 5 units = 0.25
« Last Edit: May 08, 2010, 06:40:15 am by A@di »
divine intervention!

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #207 on: May 08, 2010, 06:48:21 am »
y-axis : 5 units = 0.25

x-axis : 5 units = 0.25

Thanks  :)
"If A equals success, then the formula is:
A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #208 on: May 08, 2010, 07:17:20 am »
hmmm ..thts smart .. graphs ques always bug mee !! evn in maths i hate graphs .. its no like i dont kno them :P but they r really borin ..

comon more doubts .. bring it on .. im waiting :) .. tired of studyin now .. :) :)

Offline $H00t!N& $t@r

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #209 on: May 08, 2010, 09:00:10 am »
Sorry, I have another question...
 http://www.freeexampapers.us/IGCSE/Physics/CIE/2005%20Nov/0625_w05_qp_6.pdf

question 2a. I always get confused with such questions!!  >:(

"If A equals success, then the formula is:
A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein