A and B are two sphere made of same material. Radius of A is double that of B and initially they are at same temperature (T). Both of them are kept far apart in a room at temperature `T_(0)(lt T)`. Calculate the ratio of initial rate of cooling (i.e. rate of fall of temperature) of sphere A and B if
(a) the spheres are solid,
(b) the spheres are hollow made of thin sheets of same thickness

Answer

(a) `(1)/(2)` (b) 1