in an experiment the temperature of a solution inside a refrigerator decreases by 1.2 C perminute. ifthe original temperature of the solution is 28C find
(A)the temperature of the solution after half an hour
(B)the time taken for the temperature of the solution to drop to -20C
llllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
2006-12-29 11:32 pm
回答 (2)
2006-12-29 11:48 pm
✔ 最佳答案
(A)28oC – 1.2 oC x 30
= 28 oC - 36 oC
= -8 oC
(B)
Let T minutes be the time taken for the temperature of the solution to drop to -20 oC, we have:
28 oC – 1.2 oC T = -20 oC
28 oC + 20 oC = 1.2 oC T
48 oC = 1.2 oC T
T = 48 oC ÷ 1.2 oC
T = 40
∴ The time taken for the temperature of the solution to drop to -20 oC is 40 minutes
2006-12-29 11:46 pm
(A)28-(1.2x30)
=28-36
=-8
(B)-8+20/1.2
=12/1.2
=10
2006-12-29 15:48:53 補充：
?
=28-36
=-8
(B)-8+20/1.2
=12/1.2
=10
2006-12-29 15:48:53 補充：
?
收錄日期: 2021-04-12 18:25:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061229000051KK01567