It takes 10 minutes to cool a liquid from 61° C to 59° C. If room temperature is 30° C then find the time taken in cooling from 51° C to 49° C.

Question

It takes 10 minutes to cool a liquid from 61° C to 59° C. If room temperature is 30° C then find the time taken in cooling from 51° C to 49° C. (A) 15 min (B) 12 min (C) 18 min (D) 20 min

Tardigrade Admin · Accepted Answer

In first case (61-59/10)=K[(61+59/2)-30] (i) In second case (51-49/t)=K[(51+49/2)-30] (ii) By solving t=15 min.

Q. It takes $10$ minutes to cool a liquid from $6 1^{\circ} C$ to $5 9^{\circ} C$ . If room temperature is $3 0^{\circ} C$ then find the time taken in cooling from $5 1^{\circ} C$ to $4 9^{\circ} C$ .

15 min

12 min

18 min

20 min

In first case $\frac{61 - 59}{10} = K [\frac{61 + 59}{2} - 30]$ (i)
In second case $\frac{51 - 49}{t} = K [\frac{51 + 49}{2} - 30]$ (ii)
By solving $t = 15 min$ .

Q. It takes 10 minutes to cool a liquid from 61∘C to 59∘C. If room temperature is 30∘C then find the time taken in cooling from 51∘C to 49∘C.