Four spheres A, B, C and D are of the same ra | vedclass

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(C) The rate of cooling $R_F = \frac{d	heta}{dt}$ is given by Newton's Law of Cooling as $R_F \propto \frac{1}{ms}$,where $m$ is the mass and $s$ is

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$D$

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(C) The rate of cooling $R_F = \frac{d	heta}{dt}$ is given by Newton's Law of Cooling as $R_F \propto \frac{1}{ms}$,where $m$ is the mass and $s$ is the specific heat capacity.Since the spheres have the same radius,their volumes $V$ are equal. Mass $m = ho V$,where $ho$ is the density.Thus,$R_F \propto \frac{1}{(ho V)s} \propto \frac{1}{ho s}$.We need to calculate the product $ho s$ for each sphere:For $A$: $ho s = 6 	imes 2 = 12$For $B$: $ho s = 3 	imes 5 = 15$For $C$: $ho s = 4 	imes 4 = 16$For $D$: $ho s = 5 	imes 6 = 30$The rate of cooling is slowest when the product $ho s$ is maximum.Comparing the values $12, 15, 16, 30$,the maximum value is $30$,which corresponds to sphere $D$.

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