A body cools from `60^(@)C` to `50^(@)C` in 10 minutes . If the room temperature is `25^(@)C` and assuming Newton's law of cooling to hold good, the temperature of the body at the end of the next 10 minutes will be

Options

A. `42.85^(@)C`
B. `24^(@)C`
C. `56.85^(@)C`
D. `46.5^(@)C`

Answer

A

Explanation

`((d theta)/(dt))=k(theta_(AV)-theta_(0))`
`(60-50)/(10)=k(55-25)`
`k=(1)/(30)`
`(50-theta)/(10)=(1)/(30)((50+theta)/(2)-25)`
`theta=42.85^(@)C`