(1)m水=ρ水.V=1X10^3J/(kg.C°)x1.8x10^-3=1.8kg
(2)W电=(1kwh/3200)x80=(1/40)kwh=90000J
P实=W实/t=1800w
(3)Q=c水m水(t-to)=7.56x10^4J
η=Q/W电x100%=84%
(1)m水=ρ水.V=1X10^3J/(kg.C°)x1.8x10^-3=1.8kg
(2)W电=(1kwh/3200)x80=(1/40)kwh=90000J
P实=W实/t=1800w
(3)Q=c水m水(t-to)=7.56x10^4J
η=Q/W电x100%=84%