A solid sphere,a cube and a circular plate all made of the same material and having the same mass are heated to 300 centigrade and are allowed to cool under the same circumstances.Which of them will cool the fastest and slowest?Please explain.

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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Badiuddin

We know, the speed of cooling down is directly proportional to the exposed area. In this case, plate has greatest exposed area and the sphere has the lowest exposed area. And the cube is in the middle of these 2 . So, first, the plate will cool down, then the cube, and lastly, the sphere will cool down.

Dear Student

Please see the solution in the attachment.


I hope this answer will help you.
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Yash Chourasiya