A cup of tea cools from 80,^oC to 60,^oC in one minute. ambient temperature is 30,^oC . In cooling f

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10-2.Transmission of Heat

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A cup of tea cools from $80\,^oC$ to $60\,^oC$ in one minute. The ambient temperature is $30\,^oC$. In cooling from $60\,^oC$ to $50\,^oC$. It will take ....... $\sec$

A

$50$

B

$90$

C

$60$

D

$48$

Solution

By Newton's law of cooling

$\frac{\theta_{1}-\theta_{2}}{t}=K\left(\frac{\theta_{1}+\theta_{2}}{2}-\theta_{0}\right)$

Standard 11

Physics

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