✔ 最佳答案
total energy provide:
P= E/T
1000 = E/(10X60)
E = 1000X600
= 600000J
let the maximum amount of water boiled away be y:
0.5(4200)x(100-20) + y(2.26X10^6) = 600000
168000 + y(2260000) = 600000
y(2260000) = 432000
y = 0.191
maximum amount of water boiled away is 0.19kg