Question

一道物理题，急需帮助！只要第三问

急啊急啊

Answer 1

① a
②∵P额=U额I额
∴ I额=P额/U额
=1100W/220V
=5A
③∵I额=U额/R
∴ R=U额/I额
=220V/5A
=44Ω
I实=U实/R
=200V/44Ω
≈4.55A
P实=U实I实
=200V×4.55A
=909.09W
m水=1000kg/m3×0.0025m3(2.5L)
=2.5kg
Q吸=4200J/(kg.℃)×2.5kg×(100℃-20℃)
=840000J
W=Q吸=840000J(不计热损失)
t=W/P
=840000J/909.09W≈924s
答：.........................................................