In 5   minutes , a body cools from 75   ° C to 65   ° C at room temperature of 25   ° C . The temperature of body at the end of next 5   minutes is                   C ∘ .

Step-by-step solution

By newton's law of cooling (with approximation), Δ T Δ t = - C T ag - T s 1 st   - 10   ° C 5   min = - C 70   ° C - 25   ° C ⇒ C = 2 45   min - 1 2 nd   T - 65 5   min = - C T + 65 2 - 25 = - 2 45 T + 15 2 ⇒ 9 (   T - 65 ) = - ( T + 15 ) ⇒    10   T = 570 ⇒ T = 57   ° C