Question 205: Thermodynamics & KTG

Question

The temperature of a body in air falls from $40^{\circ} \mathrm{C}$ to $24^{\circ} \mathrm{C}$ in 4 minutes. The temperature of the air is $16^{\circ} \mathrm{C}$. The temperature of the body in the next 4 minutes will be :

Accepted Answer

$$\begin{aligned}
& \frac{\mathrm{T}_2-\mathrm{T}_1}{\mathrm{t}}=\mathrm{K}\left[\mathrm{~T}_{	ext {avg }}-\mathrm{T}_{\mathrm{s}}ight] \
& \mathrm{T}_1=24^{\circ} \mathrm{C} ; \mathrm{T}_2=40^{\circ} \mathrm{C}, \mathrm{t}=4, \mathrm{~T}_{\mathrm{s}}=16^{\circ} \mathrm{C} \
& \frac{40-24}{4}=\mathrm{K}[32-16] \
& \mathrm{K}=\frac{4}{16}=\frac{1}{4} \
& 	ext { Now } \frac{24-\mathrm{T}}{4}=\mathrm{K}\left[\frac{\mathrm{~T}+24}{2}-16ight] \
& 24-\mathrm{T}=\frac{\mathrm{T}-16}{2}+16 \
& \frac{3 \mathrm{~T}}{2}=28 \
& \mathrm{~T}=\frac{56}{3} \mathrm{C}
\end{aligned}$$

Answer

$\frac{28}{3}{ }^{\circ} \mathrm{C}$

Answer

$\frac{56}{3}{ }^{\circ} \mathrm{C}$

Answer

$\frac{42}{3}{ }^{\circ} \mathrm{C}$

Answer

$\frac{14}{3}{ }^{\circ} \mathrm{C}$

Thermodynamics & KTG

The temperature of a body in air falls from 40^{\circ} \mathrm{C} to 24^{\circ} \mathrm{C} in 4 minutes. The temperature of the air is 16^{\circ} \mathrm{C}. The temperature of the body in the next 4 minutes will be :

Choose the correct answer: