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?
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
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... ?
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... ?
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
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