1)Q=cm(t-t0)=cpV(t-t0)=4.2*10^3*10^3*10^(-3)*(100-20)=3.36X10^5J
2) Q总 =P t = 1000W * 6*60S = 3.6X10^5J
η=Q/Q 总= 3.36X10^5J/3.6X10^5J =93.3%
1)Q=cm(t-t0)=cpV(t-t0)=4.2*10^3*10^3*10^(-3)*(100-20)=3.36X10^5J
2) Q总 =P t = 1000W * 6*60S = 3.6X10^5J
η=Q/Q 总= 3.36X10^5J/3.6X10^5J =93.3%