In a room where the temperature is ${30^o}C$, a body cools from ${61^o}C$ to ${59^o}C$ in $4$ minutes. The time (in min.) taken by the body to cool from ${51^0}C$ to ${49^0}C$ will be ....... $\min$
Medium
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(b) First case, $\frac{{61 - 59}}{4} = K\left[ {\frac{{61 + 59}}{2} - 30} \right]$…..$(i)$
Second case, $\frac{{51 - 49}}{t} = K\left[ {\frac{{51 + 49}}{2} - 30} \right]$ …..$(ii)$
By solving equation $(i)$ and $(ii)$ we get
$t = 6 min$ .
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