Hot water cools from ${60^o}C$ to ${50^o}C$ in the first $10$ minutes and to ${42^o}C$ in the next $10$ minutes. The temperature of the surrounding is ......... $^oC$
$5$
$10$
$15$
$20$
Write Newton's law of cooling and obtain its equations.
Newton's law of cooling is a special case of
A black body calorimeter filled with hot water cools from $60^o C$ to $50^o C$ in $4 \,\,min$ and $40^o C$ to $30^o C$ in $8 \,\min$. The approximate temperature of surrounding is ........ $^oC$
A body takes $4$ minutes to cool from ${100^o}C$ to ${70^o}C$. To cool from ${70^o}C$ to ${40^o}C$ it will take ........ $\min.$ (room temperature is ${15^o}C$)
A solid cube and a solid sphere of the same material have equal surface area. Both are at the same temperature ${120^o}C$, then