Re: [求救]誰會算這題呀 有學過工程數學幫幫忙
※ 引述《tony90981 (全力拼台大研究所)》之銘言：
: A small metal bar, whose initial temperature was 20度C,is
: dropped into a container of boiling water. How long will it
: take the bar to reach 90度C if it is known that is temperature
: increased 2度C in 1 second? How long will it take the bar to
: reach 98度C? 答案分別是 82.1 seconds ;145.7 seconds
: 有誰會呀 我只要知道如何列式就可以了 !!! 救命呀!!!
dT/dt=k(100-T) 又 initial condition說
2=k(100-20) 所以 k=1/40
所以 dT/dt=1/40(100-T)
去解微分方程 但是我算出來的跟答案不一樣 而且會有負號 幹
我是弱砲 對不起
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