Question

A body cools from ${80}^{\circ }Cto{64}^{\circ }C$ in 5 min and same body cools from ${80}^{\circ }Cto{52}^{\circ }C$ in 10 min, what is
the temperature of the surrounding?

• A. ${24}^{\circ }C$
• B. ${28}^{\circ }C$
• C. ${22}^{\circ }C$
• D. ${25}^{\circ }C$

Answer 1

The correct option is A ${24}^{\circ }C$

According to Newton’s law of cooling,
$\frac{80-64}{5}=k[\frac{80+64}{2}-T].....\left(i\right)and\frac{80-52}{10}=k[\frac{80+52}{2}-T]....\left(ii\right)c$
Where T is the temperature of the surronding Solving Equations (i) and (ii), we get
$T={24}^{\circ }C$