Newton’s Law of Cooling – Rankers Physics

Uncategorized: Practice Problem & Solution

A body cools from $80^circtext{C}$ to $70^circtext{C}$ in $12text{ minutes}$ and from $70^circtext{C}$ to $60^circtext{C}$ in time $t$ minutes. The value of $t$ is (temperature of surrounding is $40^circtext{C}$)
13.8
16.8
18.8
20.8

Solution Explained:

To solve this problem, we apply the core principles of Uncategorized. Understanding the underlying formula is key to arriving at the correct answer below:

Using Newton's law of cooling: $frac{T_1 - T_2}{t} = Kleft(frac{T_1 + T_2}{2} - T_sright)$. From the first interval, we get $K = frac{1}{42}$. For the second interval, we obtain $t = 16.8text{ minutes}$.

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