Heat and Thermodynamics 3 Question 21
21. Two metallic spheres and are made of the same material and have got identical surface finish. The mass of is thrice that of . Both the spheres are heated to the same high temperature and placed in the same room having lower temperature but are thermally insulated from each other. The ratio of the initial rate of cooling of to that of is
(a)
(b)
(c)
(d)
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Solution:
- The rate at which energy radiates from the object is
Since,
Also, since
Hence,
For the given two bodies