更新1:
Given c(coke) = 5300 J/kg/℃
physics F.3
2007-10-30 2:07 am
Some ice cubes(0.1kg, 0℃) are added to a glass of Coke(0.3kg, 25℃). If no heat is lost to the surroundings, find the final temperature T of the mixture. Is T higher or lower in reality?
回答 (2)
2007-10-30 2:18 am
✔ 最佳答案
你要俾Coke ge specific heat capacity同埋冰轉水所需ge能里先計到....好似叫lenxxxt heat咁ge嘢..
咁先計到...
2007-10-29 18:49:15 補充：
冰熔解的比潛熱係:3.34x10^5Jkg^-1Given c(coke) = 5300 J/kg/℃ ice gain energy=coke loss energy3.34x10^5x0.1 0.1x4200x(T-0)=0.3x(25-T)x530033400 420T=39750-1590T420T 1590T=39750-334002010T=6350T=3.16℃
2007-10-29 18:49:29 補充：
T is higher in reality...因為室溫係25℃mixture ge 溫度比室溫低..so 佢會gain energy by radiation and conduction from surrounding.(主要是 radiation ..因空氣係不良導體..so conduction effect得唔大..
2007-10-30 2:37 am
The specific latent haet of fushion of ice is 3.34X10^5 J/kg
The energy released by the coke
=(0.3)(5300)(25 - T) = 39750 - 1590T
The energy gained by the icw
=(0.1)(334000) + (0.1)(4200)(T - 0) = 33400 + 420T
39750 - 1590T = 33400 + 420T
2010T = 6350
T = 3.15920398℃
T = 3.16℃
The final temperature of coke was 3.16℃
The T must be higher than in reality. It is because there is energy exchange between the mixture and the surrounding.
2007-10-29 18:38:48 補充：
打錯字…The energy gained by the ice
The energy released by the coke
=(0.3)(5300)(25 - T) = 39750 - 1590T
The energy gained by the icw
=(0.1)(334000) + (0.1)(4200)(T - 0) = 33400 + 420T
39750 - 1590T = 33400 + 420T
2010T = 6350
T = 3.15920398℃
T = 3.16℃
The final temperature of coke was 3.16℃
The T must be higher than in reality. It is because there is energy exchange between the mixture and the surrounding.
2007-10-29 18:38:48 補充：
打錯字…The energy gained by the ice
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