Question
A body cools in a surrounding of constant temperature $30^{\circ} \mathrm{C}$. It's heat capacity is $2 \mathrm{~J} / \mathrm{C}$. Initial temperature of the body is $40^{\circ} \mathrm{C}$. Assume Newton's law of cooling is valid. The body cools to $36^{\circ} \mathrm{C}$ in 10 minutes.In further 10 minutes it will cool from $36 \mathrm{C}$ to(a) $34.8 \mathrm{C}$(b) $32.1 \%$(c) $32.8^{\circ} \mathrm{C}$(d) $33.6^{\circ} \mathrm{C}$
Step 1
Mathematically, this can be written as: \[ \frac{d\theta}{dt} = -k(\theta - \theta_a) \] where $\theta$ is the temperature of the object, $\theta_a$ is the ambient temperature, $t$ is time, and $k$ is a constant of proportionality. Show more…
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