c of water =4200, l=2.26x10^6
a) Calculate the energy neeed to generate 500g of steam from the water at 25C.
b) input of power is 600W. effeiciency of steamer is 75%. find the min. time to generate 500g of steam from water at 25C.
c) cost of electricityis $0.85 per kWh, caculate the cost to generate 500g of steam from water at 25C, using the result from (b).
Thanks! :)
A question on the topic Heat
2007-06-10 7:15 am
回答 (1)
2007-06-10 7:41 am
✔ 最佳答案
a) E = mcΔT + mlE = (0.5)(4200)(100-25) + (0.5)(2.26x10^6)
= 1287500J
b) E = Pt
1287500 = (600)(75%)t
t = 47.7 min ( cor. to 3 s.f.)
c) The number of kWh to generate the steam from water:
(0.6kW)(47.7/ 60)h
= 0.477kWh
Therefore the total cost:
$0.85 X 0.477 = $0.405 ( cor. to 3 s.f.)
參考: My Physics Knowledge
收錄日期: 2021-04-12 21:45:14
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