A metal rod is taken from a furnace at and immediately immersed in a liquid bath…

PHYSICS · Subjective · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter

Problem

A metal rod is taken from a furnace at

100^{\circ}\text{C}

and immediately immersed in a liquid bath whose temperature is

86^{\circ}\text{F}

. The temperature of the rod changes with a constant

k=0.05\;\text{min}^{-1}

. How long (in minutes, correct to two decimal places) will it take for the rod to cool to

50^{\circ}\text{C}

? (Use the relation

F=1.8\,C+32

to convert units.)