Hot water kept in a beaker placed in a room cools from ${70^o}C$ to $60°C$ in $4$ minutes. The time taken by it to cool from ${69^o}C$ to ${59^o}c$ will be
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(b) Rate of cooling $ = \frac{{ - d\theta }}{{dt}} \propto \left( {\frac{{{\theta _1} + {\theta _2}}}{2} - {\theta _0}} \right)$
In second case average temperature will be less hence rate of cooling will be less. Therefore time taken will be more than $4$ minutes.
In second case average temperature will be less hence rate of cooling will be less. Therefore time taken will be more than $4$ minutes.
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