According to Newton's Law of Cooling, the rate of cooling of an object is proportional to the temperature difference between the object and its surroundings. That is, dθ/dt ∝ (θ - θ₀), where θ is the object's temperature and θ₀ is the surrounding temperature. For small temperature ranges, the average rate of cooling in an interval can be approximated as proportional to the average temperature difference in that interval.
A cup of tea is placed at a table, and the room temperature is 35°C. The tea cools from 90°C to 70°C in 5 minutes. Which one among the following is the correct time taken for the tea to cool from 70°C to 50°C ?
Asked in UPSC Geoscientist 2024 · Topic: Heat and Thermodynamics (Blackbody Radiation and Laws (Stefan-Boltzmann, Wien's Displacement))
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