急急急............物理科--------exam 20分

水的比熱容量係4200
energy to make water from 20℃ to 0℃ = 1x4200x(20-0)= 84000J
水的熔解比潛熱係3.34x 10^5
so energy to make water to ice is 3.34x10^5
so total energy is 4.18 x10^5
2mins = 120s
so 製冰機平均每秒從水中移去的能量= 4.18x10^5/ 120 = 3483.33333333333J