Heat and Thermal ExpansionHard
Question
A body cools in a surrounding which at a constant temperature of θ0 Assume that it obeys Newton′s law of cooling. Its temperature θ is plotted against time t. Tangent are drawn to the curve at the points P (θ - θ2) and Q (θ - θ2). These tangents meet the time axis at angles of φ1 and φ2 as shown, then :-
Options
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Solution
Newton’s low of cooling implies that rate of cooling is proportional ti temperature difference if the temperature difference between body and surrounding is small.
Then
= tan φ2α (θ2 - θ0) and
= tan φ1α (θ1 - θ0) ⇒ 
Then
= tan φ2α (θ2 - θ0) and = tan φ1α (θ1 - θ0) ⇒ Create a free account to view solution
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