解: (1)根据P=UI得,1100W/220V=5A; (2) 方法一:根据W=Pt得,微波炉消耗的电能是:W=Pt=1100W×60s=6.6×104J; 方法二:根据W=Pt得,微波炉消耗的电能: W=Pt=1.1KW×h≈0.0183kWh; 方法三:W=UIt=220V×5A×60s=6.6×104J (3)根据得:1.0×103kg/m3×275×10-6m3=0.275kg,Q=cm(t-t0)得,水吸收的热量:Q吸=c水m水(t-t0)=4.2×103J/(kg·℃)×0.275kg×(40℃-20℃)=2.31×104J。 |