Question

If a body cools from $80^{\circ}\text{C}$ to $50^{\circ}\text{C}$ in the room temperature of $25^{\circ}\text{C}$ in 30 minutes, then the temperature of the body after 1 hour is

• A. $31.36^{\circ}\text{C}$
• B. $32.25^{\circ}\text{C}$
• C. $36.36^{\circ}\text{C}$
• D. $33.25^{\circ}\text{C}$

Hint:

For Newton's Law of Cooling, always remember the formula $\theta(t) = \theta_s + Ce^{-kt}$. Use initial conditions to find $C$ and then another data point to find $k$. If time is doubled, the cooling factor $e^{-kt}$ becomes squared.

Answer 1

The Correct Option is C