A body cools from 80°C to 60° in 5 minutes. The temperature for the surrounding is 20°C. The time it takes to cool from 60°C to 40°C is
A
450s
B
420s
C
500s
D
s
Text Solution
Verified by ExpertsThe correct answer is:
C
The formula to calculate the rate of cooling of the object is given by
...
For the first case, it can be written, using equation that
4=50K...
If t is the required time for the second case, from equation , it can be written that
...
Divide equation by equation and solve to calculate the required time.
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