Q. The temperature of a liquid drops from $365K$ to $361\ K$ in $2\ minutes$. Find the time during which temperature of the liquid drops from $344\ K$ to $342K$. Temperature of room is $293\ K$
A) $84\ s$
B) $72\ s$
C) $66\ s$
D) $60\ s$
Explanation
(a) $\frac{365 - 361}{2} = K\left\lbrack \frac{365 + 361}{2} - 293 \right\rbrack = 70\ K \Rightarrow K = \frac{1}{35}$
Again $\frac{344 - 342}{t} = \frac{1}{35}\left\lbrack \frac{344 + 342}{2} - 293 \right\rbrack = \frac{10}{7}$
$\Rightarrow t = \frac{14}{10}\ min\ = \frac{14}{10} \times 60 = 84\ s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.