To do an experimental verification of Newton’s law of cooling, we need to take the ‘temperature’ vs ‘time’ readings, of a hot body, kept in given surroundings. An appropriate choice, of the ‘hot body’ and the ‘surroundings’, would then be
(1) [A hot metal sphere]; and [a ‘closed enclosure’].
(2) [A hot metal sphere]; [a stone plate to hold the sphere and kept in an uncovered enclosure].
(3) [An uncovered calorimeter containing hot water that is constantly being stirred]; [a slab on an open window or a table under a fan].
(4) [A fully covered calorimeter containing hot water]; [a corner of the room away from any open window or a fan].