A body takes 4min. to cool from 373K to 343K. If room temperature is 288K, the time taken to cool from 343K to313K will be :

Apply Newtons Law of cooling  formula to get the answer

The Newton’s law of cooling is given by,

dT/dt = k(Tt – Ts)

Where

Tt = temperature at time t and

Ts = temperature of the surrounding,

 k = constant.

The Newton’s Law of Cooling Formula is expressed by

T(t) = Ts + (T0 – Ts) e-Kt

Where,

t = time,

T(t) = temperature of the given body at time t,

Ts = surrounding temperature,

To = initial temperature of the body,

k = constant.

Please note that greater the difference in temperature between the system and surrounding, more rapidly the body temperature changes.