Question

· A cup of tea cools from 71°C to 69°C in two
minutes. How much time will it také to cool from
41°C to 39°C, if the temperature of surroundings is
30°C? Assume Newton's law of cooling is
applicable.
(1) 2 minute
(2) 4 minute
(3) 6 minute
(4) 8 minute​

Answer 1

For me the answer is 2 minutes .

Explanation:

Because in the first case the temperature decreases two degree celcius in two minutes . So it meams that one degree in one minute . And in the second case also the temperature decreases two degree celcius . Hope its help and please mark as branliest answer

Answer 2

Use formula :

(T2-T1)/time =k [(T2+T1)/2 -T(atm)]

First we shall find the cooling constant K

Substituting 71 and 69 , we get K=1/40

Substituting K as 1/40 in the second equation and T1 and T2 as 41 and 39

We get final temperature 8 minutes.

Please do note that T atmosphere is the temperature of atmosphere , it can be neglected if not given