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energy heating a home?
During 2 hours one winter afternoon, when the outside temperature was 4° C, a house heated by electricity was kept at 20° C with the expenditure of 42 kwh (kilowatt·hours) of electric energy.
(a) What was the average energy leakage in joules per second (watts) through the walls of the house to the environment (the outside air and ground)?
in watts
(b) The rate at which energy is transferred between two systems due to a temperature difference is often proportional to their temperature difference. Assuming this to hold in this case, if the house temperature had been kept at 24° C (77° F), how many kwh of electricity would have been consumed?
in kwh
only one i know is
Cm(Tf - Ti) + Cm(Tf - Ti) = 0
where C is specific heat capacity
m is mass
Tf is final temp
Ti is inital temp
was going to figure out final temp using above equation and then compare that to the final temp given. but don't know the C so got stuck.
Homework Statement
During 2 hours one winter afternoon, when the outside temperature was 4° C, a house heated by electricity was kept at 20° C with the expenditure of 42 kwh (kilowatt·hours) of electric energy.
(a) What was the average energy leakage in joules per second (watts) through the walls of the house to the environment (the outside air and ground)?
in watts
(b) The rate at which energy is transferred between two systems due to a temperature difference is often proportional to their temperature difference. Assuming this to hold in this case, if the house temperature had been kept at 24° C (77° F), how many kwh of electricity would have been consumed?
in kwh
Homework Equations
only one i know is
Cm(Tf - Ti) + Cm(Tf - Ti) = 0
where C is specific heat capacity
m is mass
Tf is final temp
Ti is inital temp
The Attempt at a Solution
was going to figure out final temp using above equation and then compare that to the final temp given. but don't know the C so got stuck.