A body cools from ${60^o}C$ to ${50^o}C$ in $10$ minutes. If the room temperature is ${25^o}C$ and assuming Newton's law of cooling to hold good, the temperature of the body at the end of the next $10$ minutes will be ......... $^oC$
A body cools from ${60^o}C$ to ${50^o}C$ in $10$ minutes. If the room temperature is ${25^o}C$ and assuming Newton's law of cooling to hold good, the temperature of the body at the end of the next $10$ minutes will be ......... $^oC$
- A
$38.5$
- B
$40$
- C
$42.85$
- D
$45$
Similar Questions
The 'Kangri' is an earthen pot used to stay warm in Kashmir during the winter months. Assume that the 'Kangri' is spherical and of surface area $7 \times 10^{-2} \,m ^{2}$. It contains $300 g$ of a mixture of coal, wood and leaves with calorific value of $30 \,kJ / g$ (and provides heat with $10 \%$ efficiency). The surface temperature of the 'Kangri' is $60^{\circ} C$ and the room temperature is $0^{\circ} C$. Then, a reasonable estimate for the duration $t$ (in h) that the 'Kangri' heat will last is (take the 'Kangri' to be a black body)
The 'Kangri' is an earthen pot used to stay warm in Kashmir during the winter months. Assume that the 'Kangri' is spherical and of surface area $7 \times 10^{-2} \,m ^{2}$. It contains $300 g$ of a mixture of coal, wood and leaves with calorific value of $30 \,kJ / g$ (and provides heat with $10 \%$ efficiency). The surface temperature of the 'Kangri' is $60^{\circ} C$ and the room temperature is $0^{\circ} C$. Then, a reasonable estimate for the duration $t$ (in h) that the 'Kangri' heat will last is (take the 'Kangri' to be a black body)
- [KVPY 2020]
One day in the morning, Ramesh filled up $\frac {1}{3}$ bucket of hot water from geyser, to take bath. Remaining $\frac {2}{3}$ was to be filled by cold water (at room temperature) to bring mixture to a comfortable temperature. Suddenly Ramesh had to attend to something which would take some times, say $5-10$ $\min$ before he could take bath. Now he had two options: $(1)$ fill the remaining bucket completely by cold water and then attend to the work, $(2)$ first attend tothe work and fill the remaining bucket just before taking bath. Which option do you think would have kept water warmer ? Explain.
One day in the morning, Ramesh filled up $\frac {1}{3}$ bucket of hot water from geyser, to take bath. Remaining $\frac {2}{3}$ was to be filled by cold water (at room temperature) to bring mixture to a comfortable temperature. Suddenly Ramesh had to attend to something which would take some times, say $5-10$ $\min$ before he could take bath. Now he had two options: $(1)$ fill the remaining bucket completely by cold water and then attend to the work, $(2)$ first attend tothe work and fill the remaining bucket just before taking bath. Which option do you think would have kept water warmer ? Explain.
A body takes $T$ minutes to cool from ${62^o}C$ to ${61^o}C$ when the surrounding temperature is ${30^o}C$. The time taken by the body to cool from ${70^o}$ to $({A_1}\,{\rm{and }}{A_{\rm{2}}})$ is
A body takes $T$ minutes to cool from ${62^o}C$ to ${61^o}C$ when the surrounding temperature is ${30^o}C$. The time taken by the body to cool from ${70^o}$ to $({A_1}\,{\rm{and }}{A_{\rm{2}}})$ is
Cooling law is based upon
A body takes $5$ minutes to cool from $90^oC$ to $60^oC$. If the temperature of the surroundings is $20^oC$, the time taken by it to cool from $60^oC$ to $30^oC$ will be ...... $\min.$
A body takes $5$ minutes to cool from $90^oC$ to $60^oC$. If the temperature of the surroundings is $20^oC$, the time taken by it to cool from $60^oC$ to $30^oC$ will be ...... $\min.$