The Student Room Group

Specific heat capacity help

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Thank you
Reply 1
Original post by z_o_e
Image is below :smile:
Thank you


What are you confused about?
Isn't the specific heat capacity of water 4200J/kg/C or something like that?
So I'm guessing you would do:
0.75 * (90-30) * 4200
= 0.75 * 60 * 4200
= 189000J?
Reply 4
WIN_20160521_120420.JPG
Reply 5
Misleading question. It says how much energy is released when the temperature goes DOWN. Energy must have been absorbed by the water which is why I got a negative value
Reply 6
Original post by Nayzar
WIN_20160521_120420.JPG


Thanks

Can someone explain this please. It would be better if you don't say the answer :smile:

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Reply 7
Original post by z_o_e
Thanks

Can someone explain this please. It would be better if you don't say the answer :smile:

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150 is lost through the roof, right? The table tells us that and we can see the total is 600.
So 150/600 is the amount lost from roof and we're told the house costs £800 per year to heat.

Hopefully you have figured out how much is wasted from the roof now and to find how much money is wasted because of the amount of heat lost through the roof we use the amount we have worked out wasted from the roof and we know the house costs £800 per year to heat so we... ?
Reply 8
Original post by _Xenon_
150 is lost through the roof, right? The table tells us that and we can see the total is 600.
So 150/600 is the amount lost from roof and we're told the house costs £800 per year to heat.

Hopefully you have figured out how much is wasted from the roof now and to find how much money is wasted because of the amount of heat lost through the roof we use the amount we have worked out wasted from the roof and we know the house costs £800 per year to heat so we... ?


I did 150/600= 0.25
0.25*100= £25

Then 800/25 = £32

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Original post by z_o_e
I did 150/600= 0.25
0.25*100= £25

Then 800/25 = £32

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Quarter of energy lost is through the roof, so quarter of money lost is through the roof.
Reply 10
Original post by Vikingninja
Quarter of energy lost is through the roof, so quarter of money lost is through the roof.


Was £32 right then

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Original post by z_o_e
Was £32 right then

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No because 32 isn't a quarter of 800.
Reply 12
Original post by Vikingninja
No because 32 isn't a quarter of 800.


I give up.

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Original post by z_o_e
I did 150/600= 0.25
0.25*100= £25

Then 800/25 = £32

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No because the question tells us it costs £800 per year to heat the house and we've already worked out how much is wasted from the roof so we multiply what we worked out by that in order to find the MONEY that's wasted through the roof
Reply 14
Original post by _Xenon_
No because the question tells us it costs £800 per year to heat the house and we've already worked out how much is wasted from the roof so we multiply what we worked out by that in order to find the MONEY that's wasted through the roof


I got 200

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Correct. The answer is £200.

Do you understand or would you like me to explain some more? :smile:
Reply 16
Original post by _Xenon_
Correct. The answer is £200.

Do you understand or would you like me to explain some more? :smile:




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(edited 7 years ago)

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