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    (Original post by mathematician)
    i think they will alow radio though for def
    because it mentioned COBE satelite picked it up and COBE is a radio telescope
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    i wrote things either way! i said some water might condense and fall back in, and i also put that depending on the material of the lid, heat energy might be reflected etc..etc...
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    (Original post by Tennis)
    what did you get for the question for the lid on top. i said more heat will be trapped therefore more water will evaporate meaning a lower laten heat capactiy.

    presence of the lid...reduces the amount of boiling water spilt... si finaly mass(m2).. is higher...... m2-m1(mass of water evaporated is lower......

    l = 68400(energy)/mass so l will increase.

    (Original post by [_Z_])
    presence of the lid...reduces the amount of boiling water spilt... si finaly mass(m2).. is higher...... m2-m1(mass of water evaporated is lower......

    l = 68400(energy)/mass so l will increase.
    im not sure we knew for definite though that boiling water WAS spilling - it could have been more of a safety precaution IN CASE boiling water spilt?

    rosie
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    (Original post by Tennis)
    what did you get for the question for the lid on top. i said more heat will be trapped therefore more water will evaporate meaning a lower laten heat capactiy.
    higher latent heat ... more accurate ... most of the energy will b used to raise the internal energy as u are minimizing heat loss ... as long as all the steam can escape and heat loss from the top is minimized u should get a value closer to 2MJ
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    (Original post by yipee)
    i wrote things either way! i said some water might condense and fall back in, and i also put that depending on the material of the lid, heat energy might be reflected etc..etc...

    Wrote the same thing... sis....... m2 would increase as a result of some steam which condenses on the lid and falls back..... which would result in a higher value for l .. than the actual value.
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    if you are minimising heat lost then more of the water will evaportate resulting in a smaller latent heat not higher.
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    tennis how did u find astro, cos u were gettin very stressed about it yesterday
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    (Original post by [_Z_])
    Wrote the same thing... sis....... m2 would increase as a result of some steam which condenses on the lid and falls back..... which would result in a higher value for l .. than the actual value.
    m2 will not increase ... the whole system is on a balance ... and n eway .. it said " steam is allowed to escape " ..... so it cant condense ... btw .. condenstaion always takes place when the lid is cold ... it will attain the temp of steam and not allow condensation .... (experience from making late nite cups of joe in the electric kettle )

    (Original post by Tennis)
    if you are minimising heat lost then more of the water will evaportate resulting in a smaller latent heat not higher.
    except some can condense and fall back into the water..

    rosie
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    tennis i dont think that was the point of the question, i think it meant, although he meant to minimise the error in the value for L, what other effects might adding a lid have?! thats how i answered for anyway!

    good good...Z, feeling better now!
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    the question can be answered in different ways....
    presence of the lid: reduces water spilt.(increases l).... reduces heat loss.(decreases l)... both have opposite effects... resulting on the whole in more accurate value of l..
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    o silly me!! i forgot to add the atmospheric pressure too. oh well, i'm sure i'll get some marks for method, using the right formulae etc
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    for effieciency one i think i may have got it wrong. i said the ratio of the recorded photons and incoming photons is high. therefore more sensitive to light. i got 2k then i put radio waves. next i said they lose heat and then turn into brown dwarfs. then i put for the scale from right to left was 3000k to 10000k. the rest of question was easy. i said similair colour means similair lamda max therefore similair temperature. then the calcuation ones were easy. then i put for for the penulatimate question that it would be useufl for veiwing very distant galaxies. and finally it gives a smaller range of view as you are in the ground and can only look upwards.
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    (Original post by infekt)
    m2 will not increase ... the whole system is on a balance ... and n eway .. it said " steam is allowed to escape " ..... so it cant condense ... btw .. condenstaion always takes place when the lid is cold ... it will attain the temp of steam and not allow condensation .... (experience from making late nite cups of joe in the electric kettle )

    whether the system is on balance or not.(the value for the final mass of water is higher than should be because the steam has come back as water.. thats what i meant by increase).. he took the precaution of adding a lid.. because water was being spilt....(m2 was less than actual)..... and true... steam cant escape.... but i dont thinkthe lid was metal which being a good conductor..would attain the temp of the steam... a metal lid... would increase heat loss..... probably... a lid like polysterene... or plastic was used... this is a poor conductor..... and was initially at room temp... some steam will definately condense... and fall back as a water droplets(i dont think they were askin for that though.)... they just asked how the value of l is affected..... its affected in more ways than one....
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    (Original post by mathematician)
    first question, force examples
    weight of man standing on earth, e-m force might be two magnets touching,
    nuclear force might be the force between neutrons and protons in a nucleus.

    equal, opposite, same type of force

    next question was piss
    last part of the next question F=mv-mu/t
    F was like 34N OR 32.
    plant question was easy too.
    if the distance is reduced then the force required by gardeneer has to increase as the moment is reduced (fx)
    ionization question and range - you just had to say tht energy of particles is used for inisation and there fore the range willl be reduced as energy is lost too ionisation of sumfing like tht.
    truck question - velocity ended up being 0.06m/s
    density question was piss, thickness of lead ended up being sumfing like 7x10^-4m
    last question was tricky, the graph went down a fraction then when it went towards P itwent down then went up( repulsive force, then pushing force when it passes, then then the line goes down a fraction again until it reaches the same point as it started.
    the very last part im not too sure, i would of thought the line would have been above the line given, but according to them it should have gone under
    Not sure I agree with everything here. I didn't use imulse on the third question last part, I worked out the acceleration required, worked out the force that would be needed then added on the constant resistence force

    I think i've got everything on the plant one right except the direction of the arrow, possibly,

    Similar quantity for density, it was certainyl something ^10-4.

    I also agree with you version of the alpha particle near nucleus problem.

    (Original post by infekt)
    m2 will not increase ... the whole system is on a balance ... and n eway .. it said " steam is allowed to escape " ..... so it cant condense ... btw .. condenstaion always takes place when the lid is cold ... it will attain the temp of steam and not allow condensation .... (experience from making late nite cups of joe in the electric kettle )
    well how exactly is it a lid if it doesn't have any kind of surface on which water could condense? even a metal mesh of some kind would allow condensation

    rosie
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    dear me...
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    (Original post by [_Z_])
    the question can be answered in different ways....
    presence of the lid: reduces water spilt.(increases l).... reduces heat loss.(decreases l)... both have opposite effects... resulting on the whole in more accurate value of l..
    i argued for reducing heat loss on that one.
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    Well guys.....(and gals.lol.)..... paper is over..... nothing we can do now..

    hopefully... everyone will be satisfied with their grades when they come out..

    btw... the coordinator at my school said.. that a level results will come out one week earlier...: august 15.... ne one know nething bout this?
 
 
 

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