PhysicsNEET 2021Newton's law of cooling, Stefan's and Wien's laws

Thermal Properties of Matter

A cup of coffee cools from 90 °C to 80 °C in $t$ minutes, when the room temperature is 20 °C. The time taken by a similar cup of coffee to cool from 80 °C to 60 °C at the same room temperature of 20 °C is:

A. $\frac{13}{10} t$
B. $\frac{13}{5} t$ ✓
C. $\frac{10}{13} t$
D. $\frac{5}{13} t$

You have the answer. The worked solution — and why the other three were written — is part of a paid pack.

From Physics › Thermal Properties of Matter › Newton's law of cooling, Stefan's and Wien's laws — lectures, notes and every past question on it.

Last revised 7 Sept 2026. Found a mistake? Tell us — corrections are the fastest thing we act on.

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