City Guilds Model Questions Vol1 2021 Engineering Question 40
Practice objective / multiple choice question 40 from the 2021 City Guilds Model Questions Vol1 Engineering examination.
A steel sample initially at \(800^{\circ}\text{C}\) is cooled in oil. After 5 min its temperature is \(545^{\circ}\text{C}\) and after 15 min it is \(258^{\circ}\text{C}\). Assuming Newton's law of cooling \(T(t)=T_{\infty}+(T_{0}-T_{\infty})e^{-kt}\) with ambient temperature \(T_{\infty}=25^{\circ}\text{C}\), determine the cooling constant \(k\) (min\(^{-1}\)) and then calculate the time required for the sample to reach \(100^{\circ}\text{C}\). Give the time to one decimal place (minutes).
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About This Question
This is City Guilds Model Questions Vol1 2021 Engineering Question 40. It is one of the objective questions from the 2021 City Guilds Model Questions Vol1 Engineering examination.
Difficulty level: Medium .
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