A body initially at 60°C cools to 50°C in 10 min. What will be its temperature at the end of next 10 min. if the room temperature is 25°C. Assume Newton's law of cooling

According to Newton s law of cooling dTdt=−kT−T0where T = temperature of body and To = temperature of surroundingsNow   ∫T1T2 dTT−T0=−k∫0t dt      loge⁡T−T0T1T2=−k[t]0tor   loge⁡ T2−T0T1−T0=−ktor    loge⁡60−2550−25=−k×(10×60)       ...(1)Let T' be the temperature at the end of 10 min. In this case,     loge⁡50−25T′−25=−k×(10×60)             ...(2)Solving eqs. (1) and (2), we get    T′=42⋅85∘C