1.W=688.4-688.2=0.2kwh
12min=0.2h
P=W/t=0.2/0.2=1kw=1000W
2.W=Pt=1000W*3*60s=1.8*10^5J
Q=80%W=80%*1.8*10^5J=1.44*10^5J
Q=cm(t-t0)
t=Q/cm+t0=5.76*10^5/(4.2*10^3*1)+20=54.3摄氏度
1.W=688.4-688.2=0.2kwh
12min=0.2h
P=W/t=0.2/0.2=1kw=1000W
2.W=Pt=1000W*3*60s=1.8*10^5J
Q=80%W=80%*1.8*10^5J=1.44*10^5J
Q=cm(t-t0)
t=Q/cm+t0=5.76*10^5/(4.2*10^3*1)+20=54.3摄氏度