Question

A beaker full of hot water is kept in a room. If it cools from 80°C to 75°C in t₁ minutes, from 75°C to 70°C in t₂ minutes and from 70°C to 65°C in t₃ minutes, then

(a) t₁ < t₂ < t₃

(b) t₁ > t₂ > t₃

(c) t₁ = t₂ = t₃

(d) t₁ < t₂ = t₃

Answer 1

Correct option (a) t₁ < t₂ < t₃

Explanation:

The rate of cooling is directly proportional to the temperature difference of the body and the surroundings. So, cooling will be fastest in the first case and slowest in the third case.