An ice -making machine can change 1kg of water at 20C into ice at 0C in 2 mins.
What is the average energy removed from the water by the machine every second ?
thx
2007-04-25 17:52:34 · 1 個解答 · 發問者 ? 1 in 科學 ➔ 其他：科學
Heat removed for 20oC water to 0oC water
= mCΔT
= (1) (4200) (20-0)
= 84000 J
Heat removed for 0oC water to 0oC ice
= mL
= (1) (334000)
= 334000 J
Average energy removed per second
= (84000 + 334000) / (2 x 60)
= 3483 J s-1
2007-04-25 19:39:16 · answer #1 · answered by Uncle Michael 7 · 0⤊ 0⤋