# A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of 3000°K, which of these will cool fastest? (a) Sphere (b) Cube (c) Plate (d) None

Saurabh Koranglekar
3 years ago

Since the material is same, the density is same.
Since mass is same and density is same so all three have same volume.
For same volume, the surface area of plate is the largest and of the sphere is the smallest.same volume, the surface area of plate is the largest and of the sphere is the smallest.
The rate of loss of heat by radiation is proportional to surface area.
Vikas TU
14149 Points
3 years ago

Dear Jayakany

Here is the concept of exposed area to the atmosphere.

we know that for same volume sphere has minimum surface area,plate has maximum surface area.

so  sphere cool slowest  and plate coo fastest

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