Question

Two identical solid spheres have the same temperature. One of the sphere is cut into two identical pieces. The intact sphere radiates an energy Q during a given small time interval. During the same interval, the two hemispheres radiate a total energy Q'. The ratio Q'/Q is equal to :

Answer 1

The surface area of a sphere is 4 PI r^2 the area of the cut sphere is the area of the sphere plus 2 circles with the same radius as the sphere giving a total of 6 PI r^2 so the ratio is 6:4 or 3:2.

Answer 2

please see attached file...